Fiber reinforced metal construct for reduced fatigue and metal embrittlement in susceptible structural applications

ABSTRACT

An assembly of structural elements, having significant asymmetric engineering properties, such as iron and glass, providing fatigue resistant structural composites.

RELATED APPLICATIONS

This application claims the benefit of Provisional application Ser. No. 60/540,993 filed Feb. 2, 2004

U.S. PATENT DOCUMENTS

510 December 1837 Sorel 826 July 1838 Johnson 869 August 1838 Alger 1,374 October 1839 Sumner & Naylor 10,106 October 1853 Goodyear 11,815 October 1854 Thomin & Stumer 19,866 April 1858 Morewood & Rogers 22,864 February 1859 Gardiner 51,724 December 1865 Jenkins 59,787 November 1866 Whitling 95,017 September 1869 Grey 139,902 June 1873 Lummus 178,460 June 1876 Pauly 199,973 February 1878 Hadfield 213,015 March 1879 Wahl & Eltonhead 214,085 April 1879 Beck 222,655 December 1879 Breeding 232,122 September 1880 Hammesfahr 354,788 December 1886 Hickley 390,969 October 1888 Hooper & Clark 537,463 April 1895 Hunter 851,118 April 1907 Chadwick 893,792 July 1908 Gabriel 903,909 November 1908 Steiner 1,269,926 June 1918 Gesell 1,409,017 March 1922 Ortiz 1,684,663 February 1925 Dill 1,731,346 October 1929 Meehan 1,781,699 November 1930 Parmley 1,844,994 February 1932 van Boyen 2,035,977 March 1936 Nichols 2,078,910 April 1937 Merrill 2,111,826 March 1938 Waltman & Dillon 2,133,238 October 1938 Slayter et al. 2,155,121 April 1939 Finsterwalder 2,172,933 September 1939 Daesen & Bradley 2,255,022 September 1941 Emperger 2,303,394 December 1942 Schorer 2,319,105 May 1943 Billner 2,407,881 September 1946 Hoover & Hayes 2,435,998 February 1948 Cueni 2,453,079 November 1948 Rossmann 2,660,049 November 1953 Maney 2,758,321 August 1956 Westfall 2,781,658 February 1957 Dobell 2,796,373 June 1957 Overum 2,797,179 June 1957 Reynolds 2,824,021 February 1958 Cook & Norteman 2,857,755 October 1958 Werth 2,869,214 January 1959 Van Buren 2,940,870 June 1960 Baldwin 3,078,555 February 1963 McFarland 3,255,875 June 1966 Tierney 3,257,266 June 1966 Sapper 3,493,550 February 1970 Schmitt 3,627,466 December 1971 Steingiser, Phillips & Cass 3,627,571 December 1971 Cass & Steingiser 3,930,639 January 1976 Steinberg, et al. 3,936,341 February 1976 Nanoux 3,950,905 April 1976 Jeter 3,951,697 April 1976 Sherby et al. 3,998,602 December 1976 Horowitz, et al. 4,049,874 September 1977 Aoyama 4,105,811 August 1978 Horowitz, et al. 4,107,228 August 1978 Horowitz, et al. 4,158,082 June 1979 Belousofsky 4,272,211 June 1981 Sabel 4,327,536 May 1982 Ascher 4,789,586 December 1988 Morimura, et al. 4,842,923 June 1989 Hartman 5,219,629 June 1993 Sobolev 5,324,563 June 1994 Rogers, Crane & Rai 5,613,334 March 1997 Petrina 5,641,543 June 1997 Brooks 5,695,867 December 1997 Saitoh, et al. 6,170,209 January 2001 Dagher, et al. 6,367,208 April 2002 Campbell, et al. 6,409,433 June 2002 Hubbell, et al. 6,454,488 September 2002 Lewis, Sr., et al. 6,502,805 January 2003 Lewis, et al. 6,616,976 September 2003 Montano et al. 6,685,154 February 2004 Blyth, et al.

OTHER REFERENCES

-   Design of Concrete Structures, by Urquhart & O'Rourke, McGraw-Hill     Book Company, ©1940. -   Standard Specifications for Structural Supports for Highway Signs,     Luminaires and Traffic Signals, 4^(th) Edition, 2001, American     Association of State Highway and Transportation Officials.

BACKGROUND OF THE INVENTION

The present invention provides the means and methods for construction of fatigue resistant structural composites assembled from structural elements having significant asymmetric engineering properties. Examples of asymmetric engineering materials are iron and glass. In the case of iron, very high compressive strengths are available, relative to other commonly encountered engineering materials. Iron's high available compressive strengths are offset by tensile strengths usually in the range of commonly encountered mild-steels. As identified in the referenced present art below, iron compressive strengths in excess of 250,000 psi are commercially available. At such high compressive strength iron usually exhibits tensile strengths in the low 20,000 psi range with elongation of a few percent. As such, iron provides an example of a material having asymmetric engineering properties. In contrast, typical mid-range-strength steels usually exhibit near-symmetric tensile and compressive properties. Non-metallic structural fibers, such as fiberglass and carbon fiber are other examples of asymmetric engineering materials. In the case of fiberglass and carbon fiber, when properly aligned, bonded and anchored, provide very high tensile strengths with some configurations offering tensile strengths in excess of iron's high compressive strengths. As identified in the referenced present art below, non-metallic fiber tensile strengths in significant excess of 300,000 psi are commercially available. The present invention provides the means and methods of constructing structural composites of iron and non-metallic fiber whereby the iron is reinforced in design-driven tensile regions with high tensile strength non-metallic fiber such as fiberglass. Such iron-and-glass structural composites offer economic advantages over the present art. For example, reinforced concrete (RC) design is usually limited to concrete compressive strengths of 5,000 psi (+/−) and reinforcing steel tensile strengths of 50,000 psi (+/−). Such RC design is achieved by assuming zero elongation of the concrete element and a few percent elongation of the reinforcing steel. The present invention's design is achieved by assuming a few percent contraction or negative elongation of its compressive element, the iron, and zero elongation of it's tensile element, the fiberglass. Such a reinforced iron or reinforced ferrous structural composite allows designers to move from a composite design, such as RC, balancing composite compressive/tensile strengths of 5,000 psi/50,000 psi (+/−) to 250,000 psi/300,000 psi (+/−). Further, the present invention allows the use of very high strength steels which presently have limited use due in part to concerns about brittleness and limited resistance to physical shock. Structural application combinations of non-metallic fiber and steel or aluminum are well-known in the present art. The present invention advances the present art by first providing means and methods of utilizing iron's very high compressive strengths and by applying the general concept of prestressed RC design whereby the compressive element, iron and/or very high strength steel, is pre-contracted before attachment of the non-metallic fiber tensile element. In contrast, prestressed RC design provides for elongation of the steel tensile element before attachment (casting) of the compressive concrete element. The very high shear-transfer requirements to gain structural composite action between iron and fiber is another achievement of the present invention. I have termed this result “reinforced ferrous composite”.

The present invention is the result of numerous experiments merging Letters Patent issued to one co-inventor and prior art devices of our design with existing government requirements of the construction, performance and use of commonly encountered structural steel and iron elements with present art knowledge providing new, economic, structural composite materials configurations.

An explanation of some general structural-composite principles of the present invention may be by way of paraphrasing specific present art U.S. patents: U.S. Pat. No. 5,613,334 to Petrina (Petrina '334). Petrina '334 states (col. 1, line 24) “Concrete is strong under compression, but relatively low in strength under tension.”

The present invention (paraphrasing Petrina '334 and substituting cast iron etc. for concrete) utilizes the fact that cast iron and high-strength steels (due to both these inherent engineering properties and existing engineering design code prohibitions) are strong under compression, but relatively low in strength under (allowable) tension. Examples of aforementioned engineering design code prohibitions include Urquhart & O'Rourke's observations that (page 42-44) “(s)ome authorities prefer that bars of the structural steel grade only be used but the modern tendency is to use the intermediate grade. The brittleness of the hard or high-carbon steel is to be feared especially in light members subject to sudden impact stresses. High-carbon steel when used should be thoroughly inspected and tested in order to prevent brittle or cracked material from being used in the completed structure.”

Petrina '334 continues “When a structural member such as a beam is made of concrete, it is under both compressive stress at the top of the beam and tension at the bottom of the beam. Thus a concrete beam would tend to fail by being cracking and pulling apart at the bottom, where the stress is tensile. The same is true of . . . any other application where tensile forces will be applied to concrete.”

The present invention (paraphrasing Petrina '334) utilizes the fact that when a structural member such as a beam is made of cast iron and/or high-strength steels, it is under both compressive stress at the top of the beam and tension at the bottom of the beam. Thus a cast iron and/or high-strength steel beam (assuming a symmetrical cross-section centered on the neutral-axis and ignoring structural shape failure, as taught by U.S. Pat. No. 139,902 to Lummus, such as localized-buckling) would tend to fail by pulling apart at the bottom, where the stress is tensile. The same is true of any other application where tensile forces will be applied to cast iron and/or high-strength steels.

Petrina '334 states (col. 1, line 32) “This can be overcome by placing reinforcement where it is necessary for structural members to resist tensile forces. The result is called ‘reinforced concrete.’”

In the present invention (paraphrasing Petrina '334) this can be overcome by placing reinforcement where it is necessary for the structural members to resist tensile forces.

Petrina '334 continues, “The reinforcement is typically in the form of steel bars . . . or welded wire fabric (in the case of flat areas such as roads, floors, or other concrete slabs).”

In the present invention (paraphrasing Petrina '334 and substituting fiberglass etc. for steel bars) the reinforcement is in the form of non-metallic fiber (such as fiberglass, carbon fiber) bars and/or fabric sheet and/or plate.

Petrina '334 states (col. 1, line 39) “In a concrete beam, the steel rebar is placed in the lower part of the beam, so that the tensile forces are countered by the reinforcement. The steel reinforcement is bonded to the surrounding concrete so that stress is transferred between the two materials.”

In an embodiment of the present invention (paraphrasing Petrina '334) such as a cast iron and/or high-strength steel beam the non-metallic fiber reinforcement is placed in the lower part of the beam, so that the tensile forces are countered by the reinforcement. The non-metallic fiber reinforcement is bonded to the surrounding cast iron and/or high-strength steel so that stress is transferred between the two materials.

U.S. Pat. No. 893,792 to Gabriel (Gabriel '792). Gabriel '792 teaches that (page 1, line 59) “(i) n making the beam, a sufficient number of shear members required for with-standing the intended load, are formed . . . and are distributed along the member at distances proportioned to the load or shear distribution. They are tilted so that the planes of the arms are oblique to the rod axis and thus transverse to the shear strains.” The present invention utilizes Gabriel '792's teachings, where needed, by providing in the cast-iron or high-strength steel, geometry shear-connectors running from the tensile element(s) into the ferrous material toward the neutral-axis, such transmission extending beyond the neutral-axis into the tensile zone if necessary or desired.

Petrina '334 states (col. 1, line 44) “In a further development the steel is stretched before the development of bond between it and the surrounding concrete. When the force that produces the stretch is released, the concrete becomes precompressed in the part of the structural member that is normally the tensile zone under load. The application of loads when the structure is in service reduces the precompression, but generally tensile cracking is avoided. Such concrete is known as ‘prestressed concrete’.”

In the present invention (paraphrasing Petrina '334 and substituting prestressing the tensile member for pre-compressing the compressive member) in a further development, the cast iron and/or high-strength steel is compressed before the development of bond between it and the non-metallic fiber reinforcement. When the force that produces the compression is released, the non-metallic fiber reinforcement becomes pre-tensioned in the part of the structural member that is normally the tensile zone under load. The application of loads when the structure is in service reduces tensile stress in the cast iron and/or high-strength steel. I have termed such pre-compressed (before application of dead-loads, service-loads, etc.) reinforced ferrous composite “pre-loaded reinforced ferrous composite”.

Petrina '334's (col. 3, line 23) “FIG. 2 shows a side view of a concrete beam using the reinforcing rod of the invention, with a cut-away to show the rods.” (col. 5, line 7) “FIGS. 2 and 3 show side and end views, respectively, of a concrete beam (11). . . . ” Without addressing other aspects of the present invention, it can be simplistically stated that I substitute ferrous metal for Petrina '334's “ . . . concrete beam (11) . . . ” element in the Petrina '334 composite structure of concrete and fiber reinforcing bar. That said, given the disparity of engineering properties between concrete and steel rebar or Petrina '334's fiber bar vs the near balance in engineering properties between say cast-iron and fiberglass or carbon fiber, while the engineering design principles of composite structural design remain unaffected, the present invention's physical manifestations are significant, unanticipated, enhancements over Petrina '334 by magnitudes. For example, substitution of 200,000 psi cast-iron for a Petrina '334 device's 5,000 psi concrete radically alters structural, architectural, manufacturing and erection requirements.

Specific engineering material properties used herein (where noted, full text quoted below) are:

For the present art, Petrina '334-type devices, typically encountered concrete compressive strengths are in the 4,000 to 8,000 psi. range and typically encountered steel rebar tensile strengths are in the 60,000 to 80,000 psi. range.

The present invention allows use of structural-composite compressive-element(s), for example cast-iron, ranging from (where noted, full text quoted below) 300,000 psi (U.S. Pat. No. 4,272,211 to Sabel)[Brinell 650 to 700 see FIG. 1], 190,000 psi (U.S. Pat. No. 3,951,697 to Sherby et al.), 140,000 psi (U.S. Pat. No. 1,731,346 to Meehan)[Brinell 320 to 360 see FIG. 1], and 175,000 psi (U.S. Pat. No. 1,731,346 to Meehan)[Brinell 402 see FIG. 1] When the present invention utilizes Petrina '334 teachings of pre-loading the structural-composite via stretching the steel tensile-element, the present invention pre-loads it's structural-composite by compressing the compressive-element(s) before shear-connecting the tensile-element(s). U.S. Pat. No. 1,731,346, dated Oct. 15, 1929, to Meehan (Meehan '346) Meehan '346 teaches of cast-iron composition having elongations ranging from (see full text quoted below) 1% to 7% and some present art ductile-iron having elongation properties in excess of 10%. The present invention contemplates use of conventional means of pre-compression and/or use of thermo-contraction to “prestress” the present invention's structural-composite.

The present invention allows use of structural-composite non-metallic fiber tensile-element(s), ranging from (where noted, full text quoted below) 250,000 psi (U.S. Pat. No. 5,324,56 to Rogers, Crane & Rai), 500,000 psi (U.S. Pat. No. 4,842,923 to Hartman), 282,000 psi (U.S. Pat. No. 3,627,571 to Cass & Steingiser), 200,000 psi (U.S. Pat. No. 3,627,466 to Steingiser et al.), 119,000 psi (U.S. Pat. No. 3,255,875 to Tierney).

Critical to structural composite design is Petrina '334's observation that for steel reinforced concrete to achieve a structural composite state (col. 1, line 40) “The steel reinforcement is bonded to the surrounding concrete so that stress is transferred between the two materials.” The present invention achieves a structural composite state between ferrous structural elements and non-metallic fiber structural elements via present art means of enhanced surface adhesion and use of present art resins.

The present invention improves on U.S. Pat. No. 537,463 to Hunter (Hunter '463), which teaches of cast-iron and steel structural composite construction. Hunter '463 teaches of (page 1, line 8) “ . . . having a hard resisting surface, and a softer and more yielding backing . . . ”

An explanation of some additional general principles and addressing specifically the shear-transfer or structural bonding between the structural compressive and tensile main elements of the present invention may be by way of paraphrasing U.S. Pat. No. 5,641,543 to Brooks (Brooks '543).

Brooks '543 teaches that (col. 1, line 62) “Broadly the invention comprises a method for preparing galvanized steel stock for the application of a top coating. As is understood in the art, for galvanized steel there are typically four layers in the zinc coating. A first eta . . . layer which interfaces with the steel surface, a zeta . . . layer, a delta . . . layer and then finally a gamma . . . layer.” (col. 1, line 37) “ . . . fabricators pre-treat the zinc coating, typically by sandblasting, before application . . . . This serves to ‘roughen’ the surface. The roughened surface has an increased surface area to enhance the bonding . . . ”

The present invention's method includes, when configured with hot-dip galvanized ferrous metal element(s), (paraphrasing Brooks '543), roughing the hot-dip galvanized zinc surface to achieve a roughened surface which has an increased surface area to enhance the bonding of the aforementioned resin(s) between the structural metal element(s) and the structural non-metallic fiber element(s) of the present invention's structural composite.

Brooks '543 teaches that (col. 1, line 56) “The process of the invention treats the surface of the zinc layer to ‘roughen’ the surface without embedding impurities into the zinc.”

In the present invention, when configured with hot-dip galvanized ferrous metal element(s), unlike Brooks '543, the method includes partial or complete removal of surface zinc, uncovering some of the zinc-iron alloy layers (zeta, delta, gamma) preferably via scarfing and/or scarifying and/or abrading. Removal of the soft zinc outer surface exposes zinc-iron alloys of high shear strength. U.S. Pat. No. 2,111,826 to Waltman & Dillon (Waltman '826) teaches that (col. 1, line 11) “An examination of a regular one dip . . . ” iron article “ . . . will generally reveal a first thin layer of very fine grain structure close to the steel or iron body . . . consisting probably of FeZn₃, a second, heavier layer of long needle-like crystals protruding more or less perpendicularly to the . . . ” iron article “ . . . and consisting probably of FeZn₇, . . .” The American Galvanizers Association provides the following Diamond Pyramid Number (DPN) hardness ratings for a) zinc DPN of 70, b) typical steel DPN of 159, c) zeta zinc-iron alloy DPN of 179 and d) delta zinc-iron alloy DPN of 244. Not only are the typically out-of-sight, below the “pure” zinc eta layer, zinc-iron alloy layers “harder” than the underlying steel and as such stress-concentrating due to their “relative-stiffness” vis-à-vis the underlying steel, but in frequently occurring structural engineering applications the zinc-iron alloy layers are in the “extreme-fiber” condition of structural service loads.

Exposure of zinc-iron alloy layers allows the use of resins with zinc-catalytic “set”, on the exposed zinc-iron alloy materials which maximizes the shear developed, said resins, of course, being compatible with the non-metallic fiber's support matrix.

Example applications of the present invention in addressing specific engineering-problem-statements include the wide governmental acceptance of the Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals, 4^(th) Edition, 2001, as the structural design code and guideline for flexible civil structures having low resonant frequencies relative to their service design loadings' frequencies and exhibiting low damping structural characteristics, replacing “Strength Loads Design” with “Structural Fatigue Design”. This change in structural design approach, from one of “strength-driven” to one of “fatigue-driven” has resulted in “ . . . increased material costs . . . ” to governmental agencies of “ . . . as much as 250%”.

The present invention provides means and methods of neutralizing structural fatigue loadings and thereby allowing a return to a “strength-driven” structural design and its associated significant reduction in materials costs. The present invention allows both design of “strength-driven” structures and retrofit for existing fatigue susceptible structures. Use of such “strength-driven” structural design allows application of prestressing forces when incorporating composite elements having asymmetric strength engineering materials properties such as but not limited to iron, and/or when composite elements include the use of fatigue susceptible metal(s) such as weldments.

Fatigue cracks in aluminum and steel initiate mostly from discontinuities within these engineering materials in regions of high stresses. Repeated load cycling in regions of high stress results in progressive damage of a localized nature. Common fracture modes are intergamular and/or transgranular cleavage. This type of fatigue crack propagation is encouraged via liquid metal embrittlement which may result from welding and/or other metallurgic processes such as hot-dip galvanizing.

Due in large part to economic cost advantages, steel is frequently the engineering material of choice for structural engineering tensile and bending moment applications.

Even where economics encourage the use of concrete in structural engineering compressive strength applications, steel is used as the tensile and shear-transfer engineering material of choice. Use of steel in civil and structural engineering applications, where corrosion is expected, such as highway bridges, necessitates that the steel components are frequently protected from corrosion via the hot-dip galvanizing process. Hot-dip galvanizing results in a metallurgical formation of zinc and iron alloy layers surrounding and encapsulating the structural steel element.

The typically encountered welding operation of jointing structural metal members creates discontinuities within these engineering materials. These discontinuities are manifested in intergamular and/or transgarnular illregularities in the weldment and nearby base-metal. In the case of steel, the hot-dip galvanizing process “liquefies” and “grows” zinc-iron alloy crystalline structures of widely differing “hardnesses” within these intergarnular and/or transgarnular discontinuities.

The present invention addresses and provides relief from problems with vibration and fatigue associated with stress fluctuations and corresponding cycles of significantly below service-load levels. Just as abovementioned, “The assessment of stress fluctuations and the corresponding number of cycles for all . . . ” load “ . . . events (lifetime loading histogram) is practically impossible. With this uncertainty, the design . . . for a finite fatigue life becomes impractical.” The same is true for the assessment of service-load stress fluctuations over the service-life of structures and their individual structural elements. The present invention replaces the hot-dip galvanized surface as the “extreme-fiber” in the areas of known stress-concentrating regions such as weldments and their localized neighborhoods by addition of resin-fiberglass layer(s)

In cases where the structural composite may be subjected to loadings orthoclastically or significant force vectors resulting in bearing on fiberglass and/or resin elements of said structural composite which might lead to “crushing” of said elements, this inventor's previous U.S. Pat. No. 6,561,492's FIGS. 10, 13, & 14 illustrate the nature of allowing metallic elements of the structural composite to have partial surface to surface contact (in U.S. Pat. No. 6,561,492 said surface to surface interface being preferably wood-to-galvanized steel) and/or contact via only the resin element(s) with the overall geometry of the composite structure to provide “channels” and/or “non-bearing” spaces and/or “traces” for the fiber elements so as to allow said fiber elements to provide tensile, and/or compressive and/or shear while experiencing minimal “crushing” loads. Said “channels” or “traces” are depicted below as items #66, 70, 72, 74, etc. in U.S. Pat. No. 6,561,492's FIG. 10 and in U.S. Pat. No. 6,561,492's FIGS. 13 & 14 (including items #86, 88, etc. Other examples of said “channels” or “traces” include this inventor's (as a co-inventor) U.S. Pat. No. 6,502,805 FIG. 10 (item 58) and U.S. Pat. No. 6,502,805 FIG. 11's Item #66's and #67's formed void, shown below and (not shown) U.S. Pat. No. 6,502,805 FIG. 15B's Item #126's formed void.

In conjunction with placement of the multi-part, zinc-catalyst, resin in contact with the zinc/zinc-iron surface, the hot-dipped galvanized steel element may be heated, relative to the resin, to encourage formation of “bridging-chains” at or near the surface exposure of the intergamular and/or transgarnular discontinuities present.

The above was discovered, by research and experiments, means and methods of structural compositions allowing for the construction of metal, preferably ferrous, reinforced with non-metallic fiber, such as fiberglass, which are structurally prestress-able, providing, for a given load-case, lighter, less expensive, greater structural-fatigue-resistance, and greater physical-shock-resistance than the present art. My discoveries are founded, in part, on Letters Patent issued to me, specifically:

U.S. Pat. No. 6,367,208, Campbell, et al. ('208), issued to me, which teaches of a structural composite (col. 2, line 67) “ . . . formed of a polymer matrix and a reinforcement material extending through a tensile region.” (col. 3, line 9) “The reinforcement can be, for example, sheet steel, or fiber (cloth or strands), such as fiberglass or carbon fiber. The sheet steel is preferably in the form of one or more thin, galvanized, perforated U-channel steel sheet(s). In further preferred embodiments, the post is formed by casting the polymer in a mold with the reinforcement positioned in the mold.” Multiple full-scale testing at E-TECH Testing (Sacramento, Calif.) and Case-Western Reserve University (and published: STRUCTURES Magazine, July/August 2001, page 11) show that '208 devices provide structurally efficient and economically effective means and methods of (col. 4, line 33) “ . . . establishing a bond between the tensile face and the compressive face via shear transfer from the tensile face material and the polymer matrix of the pile's or post's material. Gluing is an option when the polymer is of sufficient shear strength and both the tensile face material and the polymer are compatible for gluing. If the polymer is not of sufficient shear strength and/or if a chemical bond, such as that formed by gluing, is not practical, and/or if there is incompatibility of materials for chemical bonding between the reinforcement and the polymer, the physical shear connection is provided either by extending the reinforcement into the polymer to a depth compatible with shear transfer requirements or by extending the polymer into and/or encapsulating all or part of the reinforcement. Alternatively, the fibers can be applied to a preform tensile face, which is then put in an injection mold where another polymer layer is molded on top of the fibers.” '208 devices address the need for a (col. 5, line 20) “ . . . polymer . . . to resist shear stress in the . . . ” structural composite “ . . . and to prevent delamination at the interface of the sheet steel . . . and the polymer . . . when a lateral load is applied.” The present invention incorporates these and other teachings of '208.

U.S. Pat. No. 6,409,433, Hubbell, et al. ('433), issued to me, which teaches to (col. 7, line 15) “ . . . place composite material(s) on the structural element's core allows for application other than providing “hoop” strengthening of core compressive materials. This allows for, but not limited to, structural beams.” Multiple full-scale testing at North Carolina State University shows that a '433 device provides a structurally efficient and economically effective (col. 6, line 5) “ . . . structural tubular element . . . . The structural tubular element . . . can be composed of various materials, . . . concrete, plastic, rubber, structural foam, etc. A friction coating can be applied on the tubular wall of the hollow conduit to provide an improved connection between the wall of the hollow conduit and the structural tubular element.” (col. 10, line 14) “ . . . to oxidize metal-components which could be intentionally placed between the composite-materials-shell . . . . Oxidation would cause the metal-oxide to “expand” pushing the “friction” coat components into, and thus increasing friction resistance . . . . ” The present invention incorporates these and other teachings of '433.

U.S. Pat. No. 6,454,488, Lewis, Sr., et al. ('488), issued to me, which teaches (col. 2, line 38) “ . . . to attenuate and dissipate the energy . . . . ” via “ . . . a monolithic synthetic resin (plastic) composition . . . . ” providing an (col. 3, line 17) “ . . . incremental force reduction . . . . ” Full-scale testing conducted by the present inventor has demonstrated the workability of '488 devices. The present invention incorporates these and other teachings of '488.

U.S. Pat. No. 6,502,805, Lewis, et al. ('805), issued to me, which teaches of a (col. 5, line 56) “ . . . tube . . . made from . . . sheet metal . . . joined at overlapping portions with sheet metal plate . . . . ” Said (col. 5, line 60) “ . . . tube . . . can be rectangular, trapezoidal, trapezium or regular polygon. Further, the individual sides of the tube may be curved, convex or concave. The cross-sectional dimensions may change along the length of tube 50. (col. 6, line 24) “ . . . a structural foam, or similar material, is enclosed in the tube . . . and thereby pressurize the tube for greater strength.” Multiple full-scale testing at E-TECH Testing (Sacramento, Calif.), Texas Transportation Institute (TTI), North Carolina State University and testing conducted privately by the present inventor has demonstrated the workability of '805 devices. The present invention incorporates these and other teachings of '805.

U.S. Pat. No. 6,685,154, Blyth, et al. ('154), issued to me, which states that (col. 1, line 15) “The prior art for providing the transfer of moment forces . . . ” within a structure system “ . . . is through the use of weldments . . . by means of welded flange plates and/or welded splice plates and/or connection plates. These jointed structures are usually designed so as to be intentionally stronger than the individually attached structural members. They are designed to carry dead load and moment forces, and load shears and torsion loads . . . ” (col. 1, line 27) “Weldments are subject to fatigue stresses. Recent structural failures and the resulting research has identified weldment fatigue failure as the primary cause of these structural failures.” Multiple full-scale testing at Case-Western Reserve University and North Carolina State University show that '154 devices provide structurally efficient and economically effective (col. 1, line 40) “means and methods for joining two or more structural members without the use of weldments . . . without suffering the fatigue-load weakness of the prior art joint designs while still able to transfer intended design loads.” The present invention incorporates these and other teachings of '154.

The following Present Art background and review is separated into:

-   Hot-Dip Galvanizing Present Art -   Metal Vibration and Bonding of Dissimilar Material(s) Present Art -   Structural Iron and Steel Present Art -   Structural Fiber Present Art -   Structural Composite Present Art -   Prestressed Structural Composite Present Art

The following Hot-Dip Galvanizing Present Art background and review focus on:

-   U.S. Pat. No. 510, dated Dec. 7, 1837, to Sorel (Sorel '510) -   U.S. Pat. No. 1,374, dated Oct. 18, 1839, to Sumner & Naylor (Sumner     '374) -   U.S. Pat. No. 10,106, dated Oct. 11, 1853, to Goodyear (Goodyear     '106) -   U.S. Pat. No. 19,866, dated Apr. 6, 1858, to Morewood & Rogers     (Morewood '866) -   U.S. Pat. No. 59,787, dated Nov. 20, 1866, to Whitling (Whitling     '787) -   U.S. Pat. No. 95,017, dated Sep. 21, 1869, to Grey (Grey '017) -   U.S. Pat. No. 213,015, dated Mar. 4, 1879, to Wahl & Eltonhead (Wahl     '015) -   U.S. Pat. No. 222,655, dated Dec. 16, 1879, to Breeding (Breeding     '655) -   U.S. Pat. No. 1,409,017, dated Mar. 7, 1922, to Ortiz (Ortiz '017) -   U.S. Pat. No. 2,111,826, dated Mar. 22, 1938, to Waltman & Dillon     (Waltman '826) -   U.S. Pat. No. 2,172,933, dated Sep. 12, 1939, to Daesen & Bradley     (Daesen '933) -   U.S. Pat. No. 2,407,881, dated Sep. 17, 1946, to Hoover & Hayes     (Hoover '881) -   U.S. Pat. No. 2,824,021, dated Feb. 18, 1958, to Cook & Norteman     (Cook '021) -   U.S. Pat. No. 2,940,870, dated Jun. 14, 1960, to Baldwin (Baldwin     '870) -   U.S. Pat. No. 3,078,555, dated Feb. 26, 1963, to McFarland     (McFarland '555)

The present invention utilizes the teachings of Sorel '510. Sorel '510 teaches that (page 1, paragraph 2) “It is well known to chemists and to all persons versed in the physical sciences that a galvanic-action is produced by the contact of two metals different in their natures, and that the most oxidizable of these two metals so brought into contact becomes positively electrified, while that which is least oxidizable becomes negatively electrified; and also that when brought into this sate the most oxidizable or positively electrified metal has a tendency to become oxidized and will abstract oxygen from compounds containing this agent, while the least oxidizable of the two metals will be protected from oxidation although exposed to agents which would oxidize it but for the contact of the negative metal.” (page 1, paragraph 3) “In the scale of the oxidability of the different metals, commencing with those which are the most oxidable, it has been found that zinc stands before iron, and it follows, therefore, that when these two metals are brought into contact a protecting influence will be exerted upon the iron by the zinc, and that the rusting of the former metal will be thereby prevented.” (page 1, paragraph 5) “ . . . the application of which my process is dependent for its efficacy . . . and the various modes which I have devised for carrying the same into operation. These modes which I have essayed are five in number, and are as follows: first, applying the zinc to the iron or steel in the manner in which tin is applied in the process of tinning . . . ” (page 1, paragraph 6) “The first process—that of coating the articles to be protected with metallic zinc . . . the articles to be coated must be rendered clean and free from oxide by processes analogous to those followed in preparing them for ordinary tinning, such as immersing them in diluted sulphuric . . . acid . . . The zinc in like manner must be poured in proper crucibles or other convenient vessels adapted to the nature and size of the articles to be operated upon . . . The articles to be coated, after being dipped into the melted zinc, are to be withdrawn slowly, that too much of the metal may not adhere to them. They are then to be thrown into cold water, . . . and dried as quickly as possible, as otherwise they may be injured by the appearance of dark spots, which it is desirable to avoid. When chains for cables or for other purposes are being withdrawn from the zinc they must be shaken until sufficiently cooled to prevent the links from being soldered together by the melted metal. . . . The melted zinc being ready and covered with sal-ammoniac, the chains are to be put into it and suffered to remain there about a minute. . . . In all cases the purest zinc should be employed.” (page 3, paragraph 1) “I do not claim to be the discover of the principle of the protection of metals from oxidation by galvanic action; nor do I claim to be the first to have proposed the employment of zinc for the preserving of iron therefrom, masses of zinc having been applied, or it having been proposed to apply it in masses to steam-engine boilers and probably to other articles with this intention; but from this my plan or mode of procedure differs as obviously as it surpasses it in efficiency and in its applicability to numerous purposes in the arts where application in masses would be impossible or altogether unavailable.” The present invention incorporates these and other teachings of Sorel '510 in general and specially Sorel '510's “first-mode”.

The present invention utilizes the teachings of Sumner '374. Sumner '374 teaches of (page 1, paragraph 1) “ . . . an improvement in the process, method, or methods by which various articles of iron or steel may be preserved from oxidation or rusting by the galvanic action produced by zinc (for which process Letters Patent were granted to M. Sorel . . . ) . . . ” (page 1, paragraph 3) “We take sheets of iron and cover them with tin . . . After having completed this operation we submit the sheets or plates so prepared to a like process, with the substitution of zinc for tin . . . When thus treated the plates or sheets of iron preserve their malleability unimpaired, and may be bent and otherwise worked as easily as before they had received such coating—a result which appears to be due to the interposition of the coating of tin between the zinc and the iron, by which interposition the chemical combination of the iron and zinc is prevented.” The present invention incorporates these and other teachings of Sumner '374 in general and specifically the bending moment resistance provided by zinc/iron alloy surface layers resulting from use of the Sorel '510 discoveries.

The present invention utilizes the teachings of Goodyear '106. Goodyear '106 teaches to (page 1, paragraph 3) “ . . . take any article of metal—say of iron, for instance—which it is desired to cover in this way and generally roughen its surface, so that the caoutchouc or gutta-percha will, when vulcanized, adhere to it more firmly.” The present invention incorporates these and other teachings of Goodyear '106.

The present invention utilizes the teachings of Morewood '866. Morewood '866 teaches (page 1, paragraph 4) “ . . . to form a new metallic surface upon sheets of iron or other metal which forms the basis of the manufacture by depositing the metal which is to form the surface from its chemical solutions by the galvanic process; . . . then finish the article by coating the sheets with a non-metallic material, composition, or varnish which is repellent of moisture, which may be used at so low a temperature as to leave the sheet metal as nearly as possible with its original form and toughness, and which protects the surfaces of the sheets from oxidation . . . we prefer for this purpose a resinous or such material . . . ” The present invention incorporates these and other teachings of Morewood '866.

The present invention utilizes the teachings of Whitling '787. Whitling '787 teaches that (page 1, paragraph 2) “The plate of iron to be coated is first . . . immers(ed) . . . in a bath . . . of . . . acid . . . A second bath . . . zinc . . . ” (page 1, paragraph 3) “The plate is then dipped in the second bath, and, while wet, is immersed in a third bath of melted tin . . . and thoroughly coating the same.” The present invention incorporates these and other teachings of Whitling '787.

The present invention utilizes the teachings of Grey '017. Grey '017 teaches how (page 1, paragraph 2) “ . . . to provide galvanized iron of more improved quality . . . ” (page 1, paragraph 3) “The invention consists in preparing the iron previous to galvanizing it, in a way calculated to provide a better article in point of toughness and appearance when finished, the zinc covering being disposed much more evenly and in large spangles over the entire surface of the sheet.” The iron (page 1, paragraph 7) “ . . . sheets are trimmed to the desired size, and are . . . ready for pickling in a bath prepared of water and sulphuric acid . . . ” (page 1, paragraph 8) “The object in pickling the iron is to remove the scale formed on the surface of the iron in the process of rolling it into sheets, it being absolutely necessary that all the scale shall be removed, and the surface of the iron perfectly clean, as when any scale remains it will not be covered in the process of galvanizing.” (page 1, paragraph 9) “After the iron has remained in the pickle long enough to have removed the scale . . . the sheets are dipped . . . into the zinc . . . ” (page 1, paragraph 10) “There is a positive injury done the iron by this process of removing the scale (which is entirely obviated by my method,) which is produced by acid penetrating the pores of the iron, when it is exposed too long in the bath, making it brittle or short in the grain, so that it is easily broken when bent.” (page 1, paragraph 11) “ . . . the acid is attaching that portion of the sheet from which the thin scale was removed in the early part of the process, and eating small holes therein, and wasting away the iron.” (page 1, paragraph 12) “The surface of the iron, as a natural consequence, is rough, and when it is galvanized, the zinc will not flow freely or smoothly upon it, which, in my opinion, prevents the formation of the large spangles, which are desirable.” The present invention incorporates these and other teachings of Grey '017.

The present invention utilizes the teachings of Wahl '015. Wahl '015 teaches that (page 1, paragraph 3) “In coating iron with zinc . . . the usual process is to first subject the objects of cast or wrought iron or steel to the process of pickling—that is, immersing in a bath of dilute sulphuric acid, then in water, then in a bath of muriatic acid, and, after drying the objects, to immerse them in the bath of molten zinc . . . The objections to this process are, first, injury to the iron, and especially if it be in the form of thin plates; by the corrosive action of the acid treatment; second, the formation of what is known as ‘dross’ in the zinc . . . bath, . . . This dross is due to the formation of a zinc-iron . . . alloy in the bath by the intimate contact of the iron with the zinc . . . and the formation of this alloy is promoted by the spongy condition to which the surface of the iron has been reduced by the acid treatment—a condition which has the twofold disadvantage of promoting the zinc-iron . . . alloy and of rendering the adhesion of a proper coating of zinc . . . tedious, and, in many cases, imperfect.” (page 1, paragraph 4) “In carrying out our invention we entirely discard the acid treatment above referred to, and adopt any process of mechanical cleansing . . . ” The present invention incorporates these and other teachings of Wahl '015.

The present invention utilizes the teachings of Breeding '655. Breeding '655 teaches that (page 1, paragraph 4) “For some arts and industries it is essential that a pipe or tube galvanized on its exterior has its interior surface uncoated or non-galvanized, to accomplish which is the object of my invention.” (page 1, paragraph 6) “In order to accomplish this result of galvanized and non-galvanized surfaces, the iron pipe, as it comes from the mill, and as is well known, has its outer and inner surfaces covered with scale, grease, &c., is closed at both ends by stoppers or caps B, and thus immersed in the acid bath, the effect whereof is to remove the scale, &c., from the exterior surface only. The pipe is now withdrawn from the bath, and the stoppers or caps are removed from the pipe, which latter is then subjected to the action of the coating metal.” (page 1, paragraph 7) “It will be seen that the inner surface of the pipe will not galvanize, owing to the existing or unremoved scale and impurities, while the outer surface will be galvanized, as usual . . . ” The present invention incorporates these and other teachings of Breeding '655.

The present invention utilizes the teachings Ortiz '017. Ortiz '017 teaches (page 1, line 21) “Many attempts have been made to provide a ferrous metal with a uniform continuous coating of aluminum, but these attempts have been unsuccessful. In one proposed process for the purpose, the ferrous metal has been dipped in a bath of molten aluminum at a temperature several hundred degrees above the melting point of aluminum, such process being based upon a supposed lack of affinity between the ferrous metal and the aluminum at temperatures nearer the melting point of aluminum. Other attempts have been made by providing the ferrous metal with a preliminary film or wash coating of a metal other than the coating metal. Both these methods have been unsuccessful, the first method causing the metal to attach the iron and produce irregular coatings of widely varying form and composition and partly destroying the outline of the article; while the latter one produces a coating, not of aluminum, but of an alloy of aluminum and the wash metal. In the latter case, a coating of pure aluminum could only be obtained by successive dippings in a series of baths, making the process commercially impracticable. Salts of heavy metals have also been used for coating the ferrous metals before dipping in molten aluminum, but in such case salts are brought into the molten aluminum which practically prevent the contact between the metals and thus a complete and continuous coating is not obtained. The salts of the heavy metals used also react with the aluminum, the result being a coating not of aluminum, but of an alloy.” (page 1, line 58) “I have discovered a method by which ferrous articles can be given an aluminum coating in the form of a dense, poreless layer united to the ferrous metal by an intermediate layer of iron aluminum alloy, the aluminum being also uniform, continuous and of a constant characteristic form and composition.” (page 1, line 66) “My process is based upon the discovery that if a cleaned ferrous article is lowered into a bath of molten aluminum at such a rate and under such conditions that the successive portions of the ferrous article are successively wetted by the molten aluminum, as evidenced by the presence of an upwardly projecting meniscus at the juncture between the ferrous article and the bath, a uniform, continuous aluminum coating is obtained of a constant characteristic form and composition. The same process may be employed for coating ferrous metals with other non-ferrous metals or alloys, and the meniscus must be constantly maintained by so regulating the speed of feeding the article in the molten bath that the meniscus will not be destroyed or inverted. The presence of this meniscus will cause oxides or foreign compounds at the juncture to be washed away from the contacting surfaces, in such a way that an actual ‘diffusion joint’ is obtained. By the term ‘diffusion joint’ in this specification, I mean the joint which occurs when two metals are brought into contact and interpenetration of one into the other taken place, or when mutual interpenetration occurs. Neither material need be at or above its melting point, though either or both may be.” (page 1, line 98) “First, the ferrous article should be cleaned as thoroughly as practicable from oxides or other impurities on the surface . . . ” (page 2, line 3) “The aluminum is melted, preferably in either an inert or reducing atmosphere . . . ” (page 2, line 14) “The surface of the aluminum bath being as clean as practicable, the ferrous article is lowered gradually in the molten aluminum bath, at such a rate that its successive portions are wetted by the molten metal.” (page 2, line 80) “ . . . the iron and molten aluminum unite with a diffusion joint, consisting of a constant and definite aluminum alloy of characteristic structure and composition. This alloy forms a continuous homogeneous coating on the surface of the ferrous metal, uniting the ferrous metal to a surface layer of pure aluminum, which lies upon the alloy. This aluminum coating is continuous, compact, dense and bright.” (page 2, line 90) “The character of the coating and the joint may be varied somewhat by varying the temperatures and the period during which the ferrous metal is held in the bath.” (page 2, line 122) “I have found that by continued high temperature heating of the article produced by my process, the alloy coating or diffusion joint will be increased in thickness . . . ” (page 3, line 4) “Even under the wide range of temperatures above described and with wide variations in time of treatment, the same alloy is formed at the juncture joint, this alloy being a chemical compound having the formula FeAL₃.” The present invention incorporates these and other teachings of Ortiz '017.

The present invention utilizes the teachings of Waltman '826. Waltman '826 teaches that (col. 1, line 11) “An examination of a regular one dip . . . ” iron article “ . . . will generally reveal a first thin layer of very fine grain structure close to the steel or iron body . . . consisting probably of FeZn₃, a second, heavier layer of long needle-like crystals protruding more or less perpendicularly to the . . . ” iron article “ . . . and consisting probably of FeZn₇, and an outside layer or coating consisting mainly of zinc, with some iron in solution.” The present invention incorporates these and other teachings of Waltman '826.

The present invention utilizes the teachings of Daesen '933. Daesen '933 teaches that (col. 1, line 10) “When a ferrous metal article . . . is dipped in molten zinc baths at galvanizing temperatures between 850° to 900° F., the zinc will alloy with the ferrous metal to form a ferro-zinc alloy coating on the article. This alloy coating contains iron and zinc in varying proportions such as FeZn; FeZn₃; and FeZn₇. The iron content in the alloy decreases with the increase in distance from the . . . ” ferrous article. Thus the inner zone of the coating adjacent the article may be FeZn; the middle zone may be FeZn₃ and the outer zone FeZn₇ to pure Zn.” The present invention incorporates these and other teachings of Daesen '933.

The present invention utilizes the teachings of Hoover '881. Hoover '881 teaches of (col. 1, line 1) “ . . . the preparation of ferrous sheets to receive resinous coatings . . . ” (col. 1, line 19) “ . . . recently . . . there has been a shift to enamels which consist of resins of thermo-setting type, or contain large quantities of such resins . . . ” (col. 2, line 1) “Without desiring to be bound by theory we believe that blistering is caused by moisture and hydrogen coming from the sheet surface and falling to escape through the enamel.” (col. 2, line 17) “In the newer types of enamel a thermo-setting resin is used which, with the vehicle, not only makes the enamel more viscous as applied, thereby yielding a heavier coating, but in itself undergoes a chemical change so that it hardens and becomes permanently infusible. This type of enamel has the advantage of setting much more quickly and attaining the maximum hardness after a shorter baking operation.” (col. 2, line 40) “In the formation of our improved sheets, the ferrous sheet metal is galvanized in any suitable way by being cleaned and treated with molten zinc . . . ” (col. 2, line 46) “The galvanized sheets are then passed through a solution containing phosphoric acid, zinc phosphate and an oxidizing agent such as sodium nitrate. This bath applies a coating of zinc phosphate to the sheet surface.” The present invention incorporates these and other teachings of Hoover '881.

The present invention utilizes the teachings of Cook '021. Cook '021 teaches that (col. 1, line 34) “Tight coat hot dip galvanizing involves the admixture with zinc in the molten coating bath of another metal or metals whose function is to inhibit the formation of brittle zinc-iron alloy, which inhibition is a prerequisite to the production of a tightly adherent coating. . . . The metal most commonly used is aluminum . . . The added metal is in very small percentage in relation to the zinc, normally constituting not over one or two percent by weight of the total content of the bath.” The present invention incorporates these and other teachings of Cook '021.

The present invention utilizes the teachings of Baldwin '870. Baldwin '870 teaches that (col. 1, line 26) “Hot dip galvanizing of iron and steel to protect the ferrous metal from corrosion has been practiced on a large scale for more than a century.” The present invention incorporates these and other teachings of Baldwin '870.

The present invention utilizes the teachings of McFarland '555. McFarland '555 teaches that (col. 1, line 16) “It has been recognized that a zinc-iron alloy surface on steel sheets presently produced by the heat treatment of galvanized steel sheets is an excellent base for paint, lacquer, and other high luster paint-type finishes. However, the intermetallic compounds forming the zinc-iron alloy, like most intermetallic compounds, are very brittle, particularly in compression, and can be pressed into many desired forms only with considerable difficulty and not without impairing the integrity of the alloy coating.” The present invention incorporates these and other teachings of McFarland '555.

The following Metal Vibration and Bonding of Dissimilar Material(s) Present Art background and review focus on:

-   U.S. Pat. No. 11,815, dated Oct. 17, 1854, to Thomin & Stumer     (Thomin '815) -   U.S. Pat. No. 1,269,926, dated Jun. 18, 1918, to Gesell (Gesell     '926) -   U.S. Pat. No. 2,078,910, dated Apr. 27, 1937, to Merrill (Merrill     '910) -   U.S. Pat. No. 2,758,321, dated Aug. 14, 1956, to Westfall (Westfall     '321) -   U.S. Pat. No. 2,797,179, dated Jun. 25, 1957, to Reynolds (Reynolds     '179) -   U.S. Pat. No. 3,257,266, dated Jun. 21, 1966, to Sapper (Sapper     '266) -   U.S. Pat. No. 3,493,550 dated Feb. 3, 1970, to Schmitt (Schmitt     '550) -   U.S. Pat. No. 3,930,639 dated Jan. 6, 1976, to Steinberg, et al.     (Steinberg, et al. '639) -   U.S. Pat. No. 3,936,341 dated Feb. 3, 1976, to Nanoux (Nanoux '341) -   U.S. Pat. No. 3,998,602 dated Dec. 21, 1976, to Horowitz, et al.     (Horowitz, et al. '602) -   U.S. Pat. No. 4,049,874 dated Sep. 20, 1977, to Aoyama (Aoyama '874) -   U.S. Pat. No. 4,105,811 dated Aug. 8, 1978, to Horowitz, et al.     (Horowitz, et al. '811) -   U.S. Pat. No. 4,107,228 dated Aug. 15, 1978, to Horowitz, et al.     (Horowitz, et al. '228) -   U.S. Pat. No. 4,158,082 dated Jun. 12, 1979 to Belousofsky     (Belousofsky '082) -   U.S. Pat. No. 4,327,536 dated May 4, 1982, to Ascher (Ascher '536) -   U.S. Pat. No. 4,789,586 dated Dec. 6, 1988, to Morimura, et al.     (Morimura, et al. '586) -   U.S. Pat. No. 5,219,629 dated Jun. 15, 1993, to Sobolev (Sobolev     '629) -   U.S. Pat. No. 5,641,543, dated Jun. 24, 1997, to Brooks (Brooks     '543) -   U.S. Pat. No. 5,695,867 dated Dec. 9, 1997, to Saitoh, et al.     (Saitoh, et al. '867) -   U.S. Pat. No. 6,543,191 dated Apr. 8, 2003, to Kress (Kress '191) -   U.S. Pat. No. 6,616,976, dated Sep. 9, 2003, to Montano et al.     (Montano et al. '976)

The present invention utilizes the teachings of Thomin '815. Thomin '815 teaches that (page 1, paragraph 2) “A difficulty occurs in enameling surfaces liable to contract and expand unequally by heat, or such as expand to an extent which throws them out of shape, owing to the enamel becoming detached from its intimate connection with the surface of the metal; . . . ” (page 1, paragraph 3) “It is usual in enameling cast-iron to mix the several materials of which the enamel is to be composed, fuse them, and when cooled pulverize and grind them into a thin paste with water. This is flooded or spread over the metallic surface and treated in a muffler to a temperature sufficient to vitrify the frit.” (page 1, paragraph 4) “Sheet-iron does not maintain its shape, but becomes cockled by the heat necessary to the process, and hence a difficulty arises. As the enamel attains a certain degree of rigidity by the evaporation of the water or other medium of flotation, the metal wrinkles and the enamel does not adhere with sufficient tenacity to follow it.” (page 1, paragraph 6) “We do not claim applying the powdered frit to a previous coating of enamel-paste while the latter is moist, such a process having been long in use . . . . ” The present invention incorporates these and other teachings of Thomin '815.

The present invention utilizes the teachings of Gesell '926. Gesell '926 teaches a (page 1, line 10) “ . . . method for preventing the rusting of iron or steel objects . . . It utilizes to this effect the protective agent which an electro-positive metal to iron creates under certain conditions on the said iron or steel object by means of a galvanic current. Another object of the present invention is to prepare the iron or steel parts in such a way that only a very slight galvanic current will be required to prevent them from rusting.” (page 1, line 35) “ . . . I make use of the phenomena of electrolysis which generates when two different metals are in contact with each other and submerged in a saline solution, and which creates a protective agent on the electro-negative metal, while the electro-positive metal is eaten away. I have found by experiment that when iron is in metallic contact with zinc, both submerged in the ocean, the iron does not rust, while the zinc is slowly consumed.” (page 1, line 49) “The rate of consumption of the electro-positive metal is proportional to the rate with which the water absorbs the protective agent on the electro-negative metal. The rate of this absorption varies with the quality of the water and is more rapid when the water is in motion than when it is quiet.” (page 1, line 57) “I explain the rusting of a painted iron plate submerged in water by the theory that the paints at present in use are not absolutely waterproof, thus giving opportunity for minute particles of water to pass through minute pores or fissures and act upon the metal, causing it to rust . . . . When the first little spots have begun to rust, they spread out under the paint and peel it off.” (page 1, line 69) “If such a painted iron plate is in metallic contact with a mass of zinc, both contacting with a saline water solution, a rusting will be prevented on the well paint covered parts by the action of the paint, and on the uncovered parts by the action of the zinc. As thus the rusting process cannot take a start, the paint is prevented from peeling off, and the consumption of zinc is slow because its electrolytic action is confined only to the minute uncovered spots.” The present invention incorporates these and other teachings of Gesell '926.

The present invention utilizes the teachings of Merrill '910. Merrill '910 teaches of a (page 1, col. 2, line 38) “ . . . method of bonding rubber to metal . . . ” The present invention incorporates these and other teachings of Merrill '910.

The present invention utilizes the teachings of Westfall '321. Westfall '321 teaches of (page 3, col. 1, line 15) “ . . . molding structural members into a plastic shell so that the members so molded in become an integral part of the shell.” The present invention incorporates these and other teachings of Westfall '321

The present invention utilizes the teachings of Reynolds '179. Reynolds '179 teaches of (page 3, col. 1, line 12) “ . . . a body of reinforced plastic materials which are laminated so as to provide a decorative outer layer, which will be reasonable proof against wear and against damage by different materials which might come in contact therewith and an inner layer which will impart the desired mechanical strength to the body as a whole.” As such the Reynolds Device is not intended to be a structural-composite. That is, the “ . . . outer layer . . . ” does not provide or enhance the overall structural capacity of the finished composite. The present invention incorporates these and other teachings of Reynolds '179

The present invention utilizes the teachings of Sapper '266. Sapper '266 teaches that (page 2, col. 1, line 12) “(b)ecause of their comparatively low cost and high strength-to-weight ratio, reinforced plastics, particularly those based on glass fiber-reinforced polyester systems are rapidly replacing other materials of construction in the manufacture of many shaped structures . . . . ” (page 2, col. 1, line 39) “A serious deficiency of glass fiber-reinforced polyester structures . . . is their poor resistance to the ravages of weathering. This deficiency manifests itself in the form of surface erosion of the structure causing a loosening and raising of the reinforcing fibers near the surface . . . the raised fibers provide multiple paths for the ingress of water into the body of the structure thus accelerating hydrolytic degradation. Attempts to correct this deficiency have included the use . . . of pure resin or resin-rich outer layers of polyester called gel coats and/or veils . . . ” (page 2, col. 1, line 60) “While these methods . . . somewhat . . . lessen . . . . the problem . . . they . . . merely postpone rather than eliminate the trouble inasmuch as the inherently unweatherable and hydrolytically unstable polyester is still exposed outermost in the structure.” The present invention incorporates these and other teachings of Sapper '266

The present invention utilizes the teachings of Schmitt '550. Schmitt '550 teaches of (page 1, col. 1, line 13) “ . . . thermoplastic polyvalent metal-bridged polymers based on major amounts of methyl methacrylate . . . . ” Schmitt establishes terms and nomenclatures as relating (page 1, col. 1, line 56) “ . . . to an improved process for effecting such bridging without loss of thermoplasticity which comprises interfacially contacting a solution or dispersion of a metal compound with a solution of a suitable polymer such that the desired bridging is effected. The term “bridging” as employed herein denotes an extrinsic association between adjacent linear polymer chains. The association has the effect of reversibly crosslinking the polymer chains even though the bridging is accomplished through ionic bonding of the two chains with a single polyvalent metal ion forming a mutual salt therebetween. In the classical meaning of the term “crosslinking,” the union of the two polymer chains is the result of covalent bonds which lead to thermset polymers. In the present case, the ionic bonds provide the strengthening effects of cross-links below the shaping temperature of the polymer but do not interfere with the mobility of the polymer chains at or above the shaping temperature.” The present invention incorporates these and other teachings of Schmitt '550.

The present invention utilizes the teachings of Steinberg, et al. '639. Steinberg, et al. '639 points out that (page 5, col. 6, line 68) Methyl Ethyl Ketone Peroxide is in fact “ . . . fire resistant . . . . ” The present invention incorporates these and other teachings of Steinberg, et al. '639.

The present invention utilizes the teachings of Nanoux '341. Nanoux '341 teaches that (page 3, col. 1, line 18) “ . . . it has not been possible hitherto to produce this combination satisfactorily because the various methods proposed for producing adhesion do not succeed in imparting sufficient resistance to delamination to this combination. Thus, for example, it has been proposed, in British Pat. No. 866,776 in the name of ARTRITE RESINS Ltd. of Mar. 12, 1957 to produce containers made of polyvinyl chloride equipped with an outer layer of reinforced polyester resin containing a crosslinking monomer (acrylate ester) which exerts a dissolving effect on polyvinyl chloride. This process in fact leads to an excellent result when the layer of polyester resin, as is claimed, is placed outside the container. It has been found, however, that if the polyester resin is placed inside the container, the adhesion between the layer of thermosetting resin and the wall of polyvinyl chloride becomes very uncertain. This defective result can be explained by the fact that, during their crosslinking, polyester resins undergo shrinkage. Consequently, this phenomenon leads to adhesion of a mechanical nature between the two layers of resin when the layer of polyester resin is placed outside the reinforced article while it promotes delamination when, on the other hand, the layer of polyester resin is placed inside the article. According to German Pat. application No. 1,958,647 in the name of KARLSKRONA-VARVET A. B. of Nov. 22, 1969, adhesion of a sheet of plastic such as polyvinyl-chloride to a layer of thermosetting resin is achieved by using, as the adhesive, a solution of polymethyl methacrylate in methylene chloride. However, the laminates produced according to this process have insufficient resistance to delamination to enable them to be used in practice.” The present invention incorporates these and other teachings of Nanoux '341.

The present invention utilizes the teachings of Horowitz, et al. '602. Horowitz, et al. '602 teaches of a (page 2, col. 2, line 33) “ . . . method . . . ” whereby a “ . . . polymeric substrate is metallized by the formation of a graft polymer coating on the substrate with the grafting and polymerization of the coating being initiated by a very small amount of silver ion. The grafting and polymerization of the coating takes place in the presence of a peroxide so that silver ion is regenerated and the reaction is autocatalytic.” The present invention incorporates these and other teachings of Horowitz, et al. '602.

The present invention utilizes the teachings of Aoyama '874. Aoyama '874 teaches of a composite structural architectural precast concrete panel wherein a “ . . . polymerization of the resinous substance and the hydration of the cement composition are carried out in the mold simultaneously.” (page 4, col. 5, line 59) “This surprising result is considered to be based on the fact that the monomer of the acrylate (non-polymerized) and the cross-linking monomer permeate the layer of the nonsetting cement composition, and the cross-linking polymerization is carried out at the surroundings of the inorganic particles, for example, the sand and gravel particles in the boundary layer thereof, and in the layer of the cement composition, the hydration of the cement proceeds in the water containing partially dissolved monomer, and the boundary layer of the resin and the cement composition is formed as a mixed layer of monomer, water and aggregates, and by water, polymerization of the monomer and hydration of the cement proceeds, with the result that an architectural precast concrete having a strong adhesive power is produced as one body.” The present invention incorporates these and other teachings of Aoyama '874.

The present invention utilizes the teachings of Horowitz, et al. '811. Horowitz, et al. '811 teaches that (page 2, col. 1, line 14) “Aluminum is an excellent structural material because of its low cost and great strength per unit weight. Aluminum has chemical characteristics, however, which make it subject to corrosion, particularly by salt water and/or salt spray. The corrosion takes the form of a white rust (aluminum oxide) and the aluminum finish itself is easily spoiled by scratching or abrasion due to its inherent softness. Further, the painting of aluminum generally does not provide satisfactory corrosion resistance since the aluminum oxide layer under the paint prevents good bonding of the paint to the aluminum surface. Accordingly, painting is generally not a satisfactory corrosion inhibitor for aluminum. The principal prior art method of protecting the finish of aluminum and aluminum alloys is that of anodizing. The process generally is performed by the immersion of aluminum in a sulfuric or chromic acid bath with the aluminum piece being the anode in an electrolytic process. This anodization forms a hard aluminum oxide coating on the aluminum surface, but the coating itself is porous and undesirably absorptive. Accordingly, the aluminum oxide layer formed by anodization may be further sealed by hydration in hot water. Another prior art approach is the use of sodium dichromate as a corrosion inhibitor and seal. The sodium dichromate provides improved corrosion resistance but leaves the coating a greenish yellow color. The corrosion inhibiting chromate ions are absorbed in the aluminum oxide matrix and are sealed in place by the formation of the hydrate. The greenish-yellow color is undesirable for many applications. The prior art approaches thus have one or more drawbacks of unwanted color or lack of sufficient abrasion and corrosion resistance or stain resistance. Further, these conventional coating processes are usually inadequate because the bonding is physical in nature and the coating can become mechanically dislodged. The porosity of prior art coatings also is a major problem in preventing corrosion over a long period of time. Accordingly, it is an object of the present invention to provide a process for the sealing of aluminum surfaces through the graft polymerization of monomers to the aluminum surface through the aluminum oxide on the aluminum surface.” The Horowitz method “ . . . provides a process by which a transparent coating is formed by an in situ graft polymerization of sealing monomers to provide a chemical bonding through the aluminum oxide on the aluminum surface. Further, the graft polymerization provides for a side group interaction for cross-linking. The process of the invention involves the use of silver ions as graft initiators for the grafting of monomers and prepolymers to the aluminum surface to be protected. The polyfunctional monomers and prepolymers which are bonded to the aluminum are vinyl monomers and polyurethane and epoxy resins and are believed to chemically bond to the aluminum oxide on the substrate. The monomers are preferably acrylic monomers having one or more hydroxy, carboxy, glycidyl or aziridinyl groups. The epoxy resins are aliphatic, cycloaliphatic or aromatic together with appropriate curing agents. The polyurethane contains up to about 6%—NCO— groups. The protective coating is very resistant to corrosion because of the chemically bonded polymeric coating and the cross-linked nature of the coating itself. It has been found that the presence of a small amount of a peroxide regenerates silver ion and also provides free radicals for further polymerization within the polymeric coating, thus acting as a catalyst for the process and accelerating the polymerization.”

“The process for coating aluminum panels, for example, comprises the steps of cleaning the panels and then immersing them in a solution containing monomers, prepolymers and the silver ion and peroxide. The panels upon removal from the monomer and prepolymer solution are then cured and dried. The epoxy, glycidyl, carboxyl, hydroxyl, isocyanate, acrylic and/or amine groups in the coating solution polymerize and cross-link to form an impervious protective coating. The coatings formed on the aluminum are clear and transparent and provide excellent corrosion resistance to salt water and the like. Further, the polymeric coating on the aluminum substrate provides a good base for the application of paints or dyes to the aluminum, if desired.” The present invention incorporates these and other teachings of Horowitz, et al. '811.

The present invention utilizes the teachings of Horowitz, et al. '228. Horowitz, et al. '228 teaches that (page 2, col. 1, line 7) “This invention pertains to novel paint compositions and the painted objects produced from the use of such compositions. More particularly, this invention relates to a universal paint composition which is capable of providing a superior surface coating chemically bonded to the object coated therewith, irrespective of the nature of the material from which the object is formed.”

“It is well-known in the art that many materials which are important in the production of manufactured articles and which require a finished or painted surface are difficult to paint effectively. Such materials as steel, aluminum and certain plastics exhibit little adhesion for many conventional paint formulations accordingly, normally require the utilization of paints which are specially tailored for the specific substrate to be painted or the utilization of a separate adhesion-promoting primer layer between the substrate and the paint layer in order to produce a painted surface meeting minimum service requirements with respect to chemical and mechanical properties. Wholely apart from such adherence difficulties, separate tailoring of paints for different substrates has generally been required in order to achieve the mechanical and chemical properties which are necessitated both by the differing physical characteristics of the substrate and the diverse environments to which the coated objects are exposed in use.” “The prior art, see for example, Bragole, U.S. Pat. No. 3,764,730 and Burlant, U.S. Pat. No. 3,437,514, discloses compositions and processes for improving the adherence of paint to various substrates by employing unsaturated monomers or polymers in conjunction with electron beam or ultraviolet radiation to generate cross-linking reactions between certain polymers. Such techniques, of course, require the use of special equipment and do not automatically produce paints which are universally applicable to a variety of substrates. Horowitz, U.S. Pat. Nos. 3,401,049 and 3,698,931 describe chemical processes for intimately bonding vinyl monomers to a substrate utilizing silver or selected silver compounds to generate free radicals on the substrate surface. However, the utilization of such molecular grafting techniques does not, in and of itself, result in a universal paint composition.”

“It is an object of the present invention to provide novel paint compositions which may be employed to produce surface coatings which may be intimately bonded to any of a wide variety of substrates.”

“It is another object of the invention to provide universal paint compositions exhibiting mechanical and chemical properties such that they have utility on a broad spectrum of substrate materials and the materials coated therewith may be employed in diverse environments.”

“Yet, another object of the invention is to provide painted objects in which the paint or coating is chemically bonded to the surface of the object.” The present invention incorporates these and other teachings of Horowitz, et al. '228

The present invention utilizes the teachings of Belousofsky '082. Belousofsky '082 teaches (page page 5, col. 4, line 17) “ . . . structure has the advantages of the outer reinforced laminate of fiberglass and the advantages of the inner cementitious ferro-cement structure 16. These two structures are integrally secured and coupled to each other so that the integral structure can be used for a wide variety of purposes including that of boats, barges and other marine structures as well as for other ferro-cement applications including decorative building panels, storage tanks whose molded similar sections can be assembled in the field, and for complete structures such as dome sections and the like which can be molded in a factory and assembled on site.”

“The coupling of the fiberglass laminate to the ferro-cement structure (or vice versa) is provided by a device which has separate elements which serve to reinforce respectively the fiberglass laminate and the armature of the cement structure. These two elements of the coupling device are themselves interengaged and formed in a strong connection which is enhanced by the reinforcing bonding of the fiberglass tape in the fiberglass laminate. Thus, the tying wires 26 for the reinforcing armature of the ferro-cement structure are anchored to the fiberglass laminate 10 by the fiberglass strips 24, which in turn reinforce the fiberglass laminate.”

“In the fabrication process of the outer laminate 10, a conventional fiberglass mold 11 (FIG. 2) is prepared in a normal manner, and its molding surface is coated with wax and polyvinyl alcohol or other acceptable parting agents for easy release of the molded object from the mold. A gelcoat 12 of desired thickness (e.g., 20-30 mils) and color is applied to the prepared mold surface and then cured. The unreinforced gelcoat 12 is then reinforced with a desired thickness of fiberglass matt, cloth or fiberglass woven roving 13 which varies for different strengths of fiberglass laminate. This reinforcement 13 is bonded with polyester resin 14 (e.g., the same as that used for the gelcoat 12) to the previously applied gelcoat 12. The desired number of reinforced layers (which varies with the application of the structure being molded) of cloth or roving 13 and resin 14 are so applied and cured. Up to this point the described method is generally similar to that of conventional structure molding of fiber-reinforced plastic.” The present invention incorporates these and other teachings of Belousofsky '082.

The present invention utilizes the teachings of Ascher '536. Ascher '536 teaches of (page 4, col. 1, line 37) “ . . . a composite building panel which comprises at least one metal reinforcing member; a layer comprised of glass fiber, said layer being fastened to said metal reinforcing member(s); and a three-dimensional, crosslinked polyester layer which abuts said fiberglass layer.” The present invention incorporates these and other teachings of Ascher '536.

The present invention utilizes the teachings of Morimura, et al. '586. Morimura, et al. '586 teaches that (page 4, col. 1, line 21) “(w)ith the popularization of vehicles such as automobile, railroad, airplane and the like, and machines such as office machine, electric goods and the like, countermeasures against noises and vibrations generated from these vehicles and machines have recently been highlighted as an urgent subject. In particular, it has strongly been demanded to reduce noises and vibrations generated from the vibration members such as members (oil pan, engine cover, ceiling member, floor member, etc.) arranged around motorcar engine, home electric appliances, metal working machines and the like. For this end, many vibration damping metal panels have been proposed or sold in markets up to the present.” The present invention incorporates these and other teachings of Morimura, et al. '586.

The present invention utilizes the teachings of Sobolev '629. Sobolev '629 teaches that (page 9, col. 1, line 18) “This invention relates to the field of structural laminates, and in particular to sandwich laminates comprising two metal sheets and a resin core. This invention also relates to the field of trailer body construction.”

The Sobolev “ . . . invention relates to structural laminates which comprise two metal sheets or two metal skin layers with a polymer core disposed between and attached to each of the inside surfaces of the metal sheets. The laminates of this invention have improved structural strength compared to prior laminates of this type. The laminates of this invention are also useful in decorative and protective applications as well as structural applications.”

“In the field of laminates, metal-resin-metal laminates are disclosed in U.S. Pat. No. 4,313,996 to Newman, et al. and U.S. Pat. No. 4,601,941 to Lutz, et al. Additional laminates are disclosed in U.S. Pat. No. 3,382,136 to Bugel, et al., U.S. Pat. No. 3,392,045 to Holub, U.S. Pat. No. 3,455,775 to Pohl, et al., U.S. Pat. No. 3,594,249 to Mueller-Tamm, et al., U.S. Pat. No. 3,623,943 to Altenpohl, et al., U.S. Pat. No. 3,655,504 to Mueller-Tamm, et al., U.S. Pat. No. 3,952,136 to Yoshikawa, et al., U.S. Pat. No. 4,330,587 to Woodbrey, U.S. Pat. No. 4,369,222 to Hedrick et al., U.S. Pat. No. 4,416,949 to Gabellieri, et al., U.S. Pat. No. 4,424,254 to Hedrick et al., U.S. Pat. No. 4,477,513 to Koga, and U.S. Pat. No. 4,594,292 to Nagai, et al. In these references, a property which is generally important is that the laminates be formable, particularly thermoformable. Other properties which have been important for metal-resin-metal laminates have been the resistance of the metal skin to heat, weather, chemicals and impact, as well as the metal skin's hardness, impermeability and strength. Multi-layer laminates have been made with multiple, alternating layers of resin and metal. Laminates in this field have been used also for heat insulation and vibration damping.”

“In U.S. Pat. No. 3,499,819 to Lewis, the resin core is a polypropylene which contains a foaming agent additive to cause the polypropylene to form a foam between the metal layers. In U.S. Pat. No. 3,560,285 to Schroter, et al. a mixture of polyether polyols is reacted with polyisocyanate and a blowing agent to form foamed urethane cores between metal layers. U.S. Pat. No. 4,421,827 to Phillips discloses metal-clad articles which use a combination of thermosetting resins and particular adhesives to bond a resin layer to a metal facing.”

“As disclosed by Vogelesang (Ind. Eng. Chem. Prod. Res. Dev. 1983, 22, 492-496) aluminum laminates with high tensile strength and fatigue resistance have also been made with multiple core layers of aramid fiber-reinforced epoxy resins. These aluminum laminates, known as “ARALL” laminates, have been developed for use as aircraft skins. See also U.S. Pat. Nos. 4,489,123 and 4,500,589 to Schijve, et al.” The present invention incorporates these and other teachings of Sobolev '629.

The present invention utilizes the teachings of Brooks '543. Brooks '543 teaches (col. 1, line 43) “It has been found that with the prior art processes for preparing the zinc surface for the finished coating, typically by sandblasting, silica particles (impurities) become embedded in the zinc layer. These silica particles subsequently are oxidized and the oxidation reaction results in corrosion, i.e. cracking and peeling of the surface. That is, the prior art processes generally treat the zinc surface with materials which remain embedded in the zinc layer. These materials are impurities in the zinc coating and form oxidation sites which are the basis for the subsequent corrosion of the top coating.” (col. 1, line 62) “Broadly the invention comprises a method for preparing galvanized steel stock for the application of a top coating. As is understood in the art, for galvanized steel there are typically four layers in the zinc coating. A first eta . . . layer which interfaces with the steel surface, a zeta . . . layer, a delta . . . layer and then finally a gamma . . . layer.” (col. 2, line 29) “The present invention broadly embodies a galvanized coating process and particularly an architectural finish which provides more than twenty years of protection against more than 10% surface rust in an ambient environment, such as outdoor ornamental fence and railing. In a preferred embodiment the steel should contain carbon below 0.25%, phosphorous below 0.5% and manganese below 1.35%. The pre-treatment comprises steel members and assemblies that have been dipped utilizing a dry kettle process and a bath of molten zinc containing nickel and other state-of-the-art alloys designed to address the particular steel composition and to ensure homogeneous metallurgical growth and greater corrosion resistance in the hot dipped galvanizing process.” (col. 2, line 44) “Within twelve hours of galvanizing, the coated surface is treated to impart to the surface a pebble-like or grain-like surface of substantial uniformity. A metallurgically compatible blasting material, specifically zinc pellets, are employed to remove the .gamma. outer layer and to form the pebble-like surface in the delta layer. This ensures that in the preparation of the surface no impurities are incorporated into the layer which would later form a site for galvanic action (rusting).” The present invention incorporates these and other teachings of Brooks '543.

The present invention utilizes the teachings of Saitoh, et al. '867. Saitoh, et al. '867 teaches of (Abstract) “A reinforcing and vibration-damping material has a laminate body which includes a constraining layer acting to reinforce an adherend to which the material is to be applied, a vibration-damping layer acting to damp vibrations in the adherend and a binder layer interposed between the constraining layer and the vibration-damping layer. Further, a hardenable pressure sensitive adhesive layer is formed on the vibration-damping layer of the laminate body, and a release liner is placed around the hardenable pressure sensitive adhesive layer. The constraining layer exhibits the advantageous effect of reinforcing the adherend, and comprises, for example, a hard material such as a metal. The binder layer comprises a pressure sensitive adhesive, a bonding agent or a hardenable pressure sensitive adhesive. The vibration-reinforcing layer comprises a viscoelastic material containing unvulcanized rubber and a vulcanizing agent for example. The hardenable pressure sensitive adhesive layer comprises a hardenable pressure sensitive adhesive which is tacky in the uncured state but has a strong adhesive force when it is cured by heating, irradiation or being blocked from air. Thus constructed, the reinforcing and vibration-damping material has the advantageous effects of damping vibrations in and reinforcing the adherend.” The present invention incorporates these and other teachings of Saitoh, et al. '867.

The present invention utilizes the teachings of Kress '191. Kress '191 teaches of a structural composite (page 16, col. 1, line 54) “ . . . compris(ing) of an outer ceramic filled gelcoat layer and a fiber reinforced filled resin layer and are attached to the respective tread surfaces and landing surface using fasteners. The fasteners preferably are captured in part in each tread member and landing member during molding so as to be integral therewith.” Kress achieves shear-transfer by means of mechanical “ . . . fasteners . . . ”, as shown in Kress FIG. 5.” The present invention incorporates these and other teachings of Kress '191.

The present invention utilizes the teachings of Montano et al. '976. Montano et al. '976 teaches of (col. 1, line 9) “The present invention is directed to a method of improving adhesion between metal and polymeric materials. More specifically, the present invention is directed to a method of improving adhesion between metal and polymeric materials by treating the metal with an epoxy resin following an adhesion promotion step.” (col. 5, line 6) “a process and composition for improving the adhesion between a metal surface and a polymeric material by treating the metal surface with an adhesion promotion composition followed by contacting the treated metal surface with an epoxy resin composition. The epoxy resin composition may be aqueous based, or organic based. The epoxy resin composition makes the metal surface more accessible to contact with a polymeric material that is coated on the metal surface. After the treated metal surface is post-treated with the epoxy resin composition, the polymeric material is placed on the surface of the metal to form a high integrity bond between the metal surface and the polymer material. Advantageously, the method and composition of the present invention provide for improved adhesion between a metal surface and a polymeric material as compared with known adhesion promoting processes. Accordingly, the adhesion between the metal surface and the polymeric material is such that . . . using the method of the present invention may be employed . . . without concern that the polymeric material may delaminate or peel from the metal surface.” The present invention incorporates these and other teachings of Montano et al. '976

The following Structural Iron and Steel Present Art background and review focus on:

-   U.S. Pat. No. 826, dated Jul. 9, 1838, to Johnson (Johnson '826) -   U.S. Pat. No. 869, dated Aug. 3, 1838, to Alger (Alger '869) -   U.S. Pat. No. 22,864, dated Feb. 8, 1859, to Gardiner (Gardiner     '864) -   U.S. Pat. No. 51,724, dated Dec. 26, 1865, to Jenkins (Jenkins '724) -   U.S. Pat. No. 178,460, dated Jun. 6, 1876, to Pauly (Pauly '460) -   U.S. Pat. No. 199,973, dated Feb. 5, 1878, to Hadfield (Hadfield     '973) -   U.S. Pat. No. 390,969, dated Oct. 9, 1888, to Hooper & Clark (Hooper     '969) -   U.S. Pat. No. 1,731,346, dated Oct. 15, 1929, to Meehan (Meehan     '346) -   U.S. Pat. No. 1,844,994, dated Feb. 16, 1932, to van Boyen (van     Boyen '994) -   U.S. Pat. No. 2,796,373, dated Jun. 18, 1957, to Overum (Overum     '373) -   U.S. Pat. No. 3,951,697, dated Apr. 20, 1976, to Sherby, Young,     Walser & Cady, Jr. (Sherby et al. '697) -   U.S. Pat. No. 4,272,211, dated Jun. 9, 1981, to Sabel (Sabel '211)

The present invention utilizes the teachings of Johnson '826. Johnson '826 teaches (page 1, paragraph 1) “ . . . a new and useful Improvement in the Art of Increasing the Strength of Wrought-Iron and Steel . . . ” (page 3, claim 2) “The increasing of the strength of bars, rods, or plates of iron by drawing them while hot through the rolls by mechanical power . . . . ” The present invention incorporates these and other teachings of Johnson '826.

The present invention utilizes the teachings of Alger '869. Alger '869 teaches of (page 1, paragraph 2) “ . . . giving to the iron-work of the whole body of the plow, consisting of the mold-board, land-side, share, movable or permanent points, and other parts requiring it, that malleability which will allow of its being altered in shape in the same way in which wrought-iron may be altered, and at the same time giving to all the cutting-edges, and to such other parts as from their exposure to wear may require it, the necessary degree of hardness and temper and the capability of being softened, drawn out, and again hardened and tempered whenever it may be desired.” (page 1, paragraph 3) “I cast the respective parts of the plow to be made of iron from any of the known patterns, and I then subject those parts to the well-known process of annealing by which cast-iron is rendered malleable. Having carried this process to the necessary extent by which the iron is brought into that state in which it is susceptible of being hardened and tempered like steel, I then harden such of the cutting-edges and other operating parts as may require it, and temper the same in the manner in which steel is ordinarily hardened and tempered. I thus obtain a plow which, while it can be manufactured at but little cost, will possess all the useful properties of a plow the body of which is made of wrought-iron, and its cutting edges and points and such other parts as are most subject to wear laid with steel.” The present invention incorporates these and other teachings of Alger '869.

The present invention utilizes the teachings of Gardiner '864. Gardiner '864 teaches of (page 1, paragraph 1) “ . . . a new and useful process for the treatment of cast-steel while passing from the molten to the hardening condition for the purpose of making unmanufactured ingots or other unmanufactured forms of steel of a peculiarly soft, tough, and malleable quality . . . ” (page 1, paragraph 3) “The nature of my discovery and invention does not consist in the gradual and prolonged cooling of the metal after melting for the purpose aforesaid; but it consists in the process of pouring the melted metal into intensely-heated molds and placing them immediately into the heated oven or furnace, then to cool and congeal away from the external atmosphere to a cherry-red heat, and then immediately plunging the ingots or bars into the highly-heated oil and retaining them immersed in it for a considerable period, as described.” The present invention incorporates these and other teachings of Gardiner '864.

The present invention utilizes the teachings of Jenkins '724. Jenkins '724 teaches of having (page 1, paragraph 2) “ . . . discovered that when the substance known in the arts as malleable cast-iron is submitted to a certain process, to be hereinafter described, it acquires entirely new properties never heretofore found in malleable cast-iron. It is rendered more tough and becomes as hard as hardened steel, so that articles requiring such properties, and which heretofore have been made of steel, and which could only be made of steel at great expense, can be produced of this new substance at much less cost, as they can be cast of the form required, subjected to the usual and well-known process of rendering cast-iron malleable, and then subjected to the process to be hereinafter described, which imparts to it the new and required properties of toughness and steel-like property of hardness.” (page 1, paragraph 3) “The articles desired to be produced are cast of the form desired in the usual way of cast-iron, and then is well known as ‘malleable cast-iron,’ and then, whether in the rough or smooth state, I heat then to what is known as a ‘cherry-heat’ heat, and at or about that heat hammer them to compact the metal. After this I heat them up again to a cherry-red heat if during the hammer operation the temperature has been materially reduced. I then sprinkle over the surface of them a composition consisting of seven parts, by weight, of prussiate of potash and one part by weight of charcoal well pulverized and mixed, and again subject them to heat until the said composition disappears, taking care to heat them up again to about a cherry-red heat and at that heat plunge them in a liquid bath . . . . When taken out this solution the malleable iron will be found to have been materially changed in its properties, to have become tough and as hard as hardened steel.” The present invention incorporates these and other teachings of Jenkins '724.

The present invention utilizes the teachings of Pauly '460. Pauly '460 teaches that (page 1, paragraph 5) “When a steel bar is hardened throughout it may be broken in pieces by a sharp blow of sufficient force, and is consequently worthless for the purpose. To meet the difficulty the bars have been made partly of steel and partly of iron, the steel exterior covering an interior plate of wrought-iron, which, of course, remained unaffected by the hardening process, and consequently prevented the bar from being broken by concussion. This construction is expensive, and does not meet the difficulties as fully as they are met by my improved bar . . . ” (page 1, paragraph 7) “The bar A, when heated to a bright cherry-red, is placed between the straight bars . . . of the dipping-frame. Those faces of the bars . . . which are in contact with the bar A are made somewhat narrower than said bar, so that a little of each edge of the bar A is exposed, to come directly in contact with the water in the dip-trough . . . . ” “The effect of the immersion in water under these circumstances is to render the edges a very hard, so that the hardest saw or file can have little effect upon them, and the middle a′ is left soft . . . and will prevent fracture by concussion.” The present invention incorporates these and other teachings of Pauly '460.

The present invention utilizes the teachings of Hadfield '973. Hadfield '973 teaches taking (page 1, paragraph 3) “ . . . either molten crucible, Bessemer, Siemens-Martin, or any other cast-steel the temper and quality of which render it suitable for the purpose, and pour such molten metal either into a suitable metallic mold or molds into a sand or other suitable composition mold or molds. I cast such shells hollow . . . . ” . . . “When so cast such steel shells are of an extremely brittle and crystalline character, and of uniform temper throughout. They are therefore too brittle for the purpose of piercing armor-plates . . . to obviate this disadvantage I subject such shells to an annealing process, which, by reducing the carbon contained therein to any desired ratio, modifies and alters the material by causing a more perfect cohesion of the particles, and consolidating the atoms or molecules into a dense, close, fine-grained steel, and, by eliminating all brittleness therefrom, greatly increases the strength and density of the shell.” (page 1, paragraph 5) “One of the principal advantages possessed by projectiles so manufactured is that the steel is not subjected either to hammering, forging, rolling, or any other mechanical treatment as hitherto practiced, thus effecting a considerable economy in the time and labor necessary for their manufacture,” The present invention incorporates these and other teachings of Hadfield '973.

The present invention utilizes the teachings of Hooper '969. Hooper '969 teaches to (page 1, line 16) “ . . . produce a cast-iron blank of a shape approximating that of the article when finished, but of considerable and uniform thickness at that portion which is subsequently to form the steel cutting edge or edges . . . . The hard casting or blank is . . . packed in iron scale, hematite ore, or other oxidizing agent, (as in the ordinary annealing process for converting cast-iron into malleable iron,) and inserted in an annealing-oven, where it is subjected to the usual temperature incident to the process of annealing. The annealing process thus begun is, however, interrupted at about two-thirds of the ordinary period which would be required to convert the article treated into malleable iron, (which of course will differ according to the character of the cast-iron composing it,) and the casting is removed. The casting will then be found to be partially decarbonized and in a uniform manner along its outer edges, which retain from one and a half to two per cent of carbon. These edges, however, have still the coarse grain or structure of the original cast-iron, and are therefore unsuitable to be sharpened and tempered at once. We therefore, after removing the blanks from the annealing-ovens, heat them to a cherry-red heat and condense the grain at the edges by blows of a hammer, at the same time working the blank out into the shape of the finished article by . . . if need be, by grinding. The blanks are thereupon reheated to the required temperature, depending upon the thickness of the . . . edge and the amount of carbon retained, and the edges are tempered by being immersed in the heated condition in water, oil, or other tempering-liquid, thereby effecting the desired molecular change and distribution of the carbon essential to . . . ” the article. The present invention incorporates these and other teachings of Hooper '969.

The present invention utilizes the teachings of Meehan '346. Meehan '346 teaches of (page 1, line 5) “ . . . a new and improved method for heat treating cast iron whereby improved physical properties are obtained . . . these results being obtainable primarily by reason of the character of the iron treated.” (page 1, line 72) “The heat treatments will, of course, vary depending upon the result desired.” (page 2, line 24) this iron contains . . . manganese as a neutralizing agent for the sulphur . . . physical characteristics of this metal Tensile strength 50,000 to 60,000 pounds per square inch. Elongation Nil. Reduction of area Nil. Brinell hardness 320 to 360. . . . ”

(page 2, line 48) “In heat treating this cupola iron two slightly different methods are used: (1) The castings are placed in an oven and heated as quickly as quickly as possible to approximately 1650° F. at which temperature they are held for from 20 to 25 hours. The casting are then remove and cooled at room temperature. After this treatment, the castings show the following physical properties: Tensile strength 80,000 to 90,000 pounds per square inch. Elongation 1% to 1½ % Reduction of area 1% to 2% Brinell hardness 220 to 240. . . . ”

(page 2, line 66) “(2) If the casting made from cupola iron is to be given somewhat different physical properties, such as greater malleability and softness, a slightly varied heat treatment is followed. In this case, the castings are placed in a furness and heated as quickly as possible to 1650° F., at which temperature they are held from 20 to 25 hours. The castings are then allowed to cool very slowly, preferably at a rate not in excess of 10° per hour, until the furness has reached a temperature of approximately 1000° F. The castings are then removed and are allowed to cool at room temperature. This heat treatment results in the following physical properties: Tensile strength 45,000 to 55,000 pounds per square inch. Elongation 4% to 6% Reduction of area 5% to 7% Brinell hardness 120 to 150. . . . ”

(page 2, line 93) “The effect of the calcium upon these heat treatments has been found to be very definite. For example, white iron test bars were all made from the same ladle of iron. This white iron without treatment by calcium and not heat treated showed: Tensile strength 24,700 pounds per square inch. Brinell 402. . . . ”

(page 2, line 105) “The same white iron not treated with calcium and given the first (1) heat treatment showed the following characteristics: Tensile strength 43,800 pounds per square inch. Brinell 394. . . . ”

(page 2, line 113) “The same metal without the calcium, and given the second (2) heat treatment showed the following: Tensile strength 48,700 pounds per square inch. Brinell 202. . . . ”

(page 2, line 122) “In neither case was there an elongation or reduction of area apparent. The calcium treated metal given the first (1) treatment showed the following characteristics: Tensile strength 62,100 pounds per square inch. Brinell 302. . . . ”

(page 3, line 1) “Given the second (2) treatment, the metal treated by calcium disclosed the following characteristics: Tensile strength 49,500 pounds per square inch. Elongation 4.7. . . . ”

(page 3, line 9) “It has also been found that the calcium employed in the form of calcium silicide will materially effect the heat treatment. The calcium silicide treated white metal shows the following characteristics, when not given the first (1) heat treatment Tensile strength 29,700 pounds per square inch. Brinell 402. . . . ”

(page 3, line 20) “When this calcium silicide metal was given heat treatment (1) it showed: Tensile strength 83,700 pounds per square inch. Brinell 212. . . .”

(page 3, line 33) “When given the second (2) treatment, the calcium silicide treated metal shows: Tensile strength 44,800 pounds per square inch. Elongation  7.8. Brinell 95. . . .”

(page 3, line 129) “ . . . in the absence of other neutralizing agents for sulphur, or any other element in the mixture, it would be necessary to use a greater amount of calcium or other alkaline earth metal. The metal then may be given either of the following heat treatments: (1) The castings are placed in a furnace and heated as quickly as possible to 1650° F. At this temperature they are held for at least approximately 16 hours, and then immediately withdrawn and allowed to cool at room temperature. The physical characteristics of castings thus treated are: Tensile strength 90,000 to 110,000 pounds per square inch. Elongation 1½% Reduction of area 1½% Brinell hardness 200 to 230. . . .”

(page 4, line 23) “If softer and more ductile castings are desired at the sacrifice of some tensile and transverse strength, the following heat treatment (2) is employed. (2) The castings are placed in a furnace and heated as quickly as possible to 1650° F. This temperature is maintained for at least approximately 16 hours when the castings are allowed to cool slowly in the furnace, preferably at a rate not exceeding 100 per hour to 1000° F., and thereafter the castings are allowed to cool at room temperature. This slightly varied heat treatment for calcium treated cupola iron produces the following physical characteristics: Tensile strength 55,000 to 65,000 pounds per square inch. Elongation 6.9% Reduction of area 10% to 12% Brinell hardness 100 to 135. . . .” (page 4, line 96) “By ‘white iron’ is meant such castings as are substantially free from graphitic carbon. By ‘gray iron’ is meant castings in which more or less graphite is present. By ‘molten white iron’ is meant such molten iron as will produce castings substantially free from graphitic carbon, and by ‘molten gray iron’ is meant such molten iron as will produce castings containing more or less graphitic carbon.” The present invention incorporates these and other teachings of Meehan '346

The present invention utilizes the teachings of van Boyen '994. Van Boyen '994 teaches that (page 1, line 6) “Articles manufactured from hard or mild steel, which must undergo a cold deformation, also undergo a substantial reduction in toughness or tenacity Cold deformation consists in working the metal at a temperature which is below the temperature of recrystallization. Recrystallization is that change in structure which is produced in cold worked material by annealing the same below the Ac₃ point. (page 1, line 20) “It may further be noted that ageing of said cold deformed articles further reduces the toughness and tenacity thereof.” The present invention incorporates these and other teachings of van Boyen '994.

The present invention utilizes the teachings of Overum '373. Overum '373 teaches that (col. 2, line 3) “The prior art is replete with disclosures of the production of malleable iron cast products in which an iron casting that is termed to be more or less a white iron casting is annealed and then heat treated to obtain carbon in the combined form. The tensile strength obtained in the prior art methods as far as is known, has a general maximum of 100,000 p.s.i.” (col. 2, line 14) “In accordance with the method fully set forth hereinafter, the present invention results in the production of a casting that is of such improved tensile strength that this factor has been increased to 200,000 p.s.i. and somewhat above.” The present invention incorporates these and other teachings of Overum '373.

The present invention utilizes the teachings of Sherby et al. '697. Sherby et al. '697 teaches of a (col. 10, line 42) “ . . . microstructure . . . ” with (col. 10, line 44) “ . . . the presence of proeutectoid cementite in spheroidized form and a transformation product consisting of fine pearlite. (col. 10, line 48) “In compression tests at room temperature, the plate exhibited a yield strength of 190 ksi . . . . ” The present invention incorporates these and other teachings of Sherby et al. '697.

The present invention utilizes the teachings of Sabel '211. Sabel '211 teaches of a (col. 1, line 54) “ . . . wear-resistant slab . . . characterized in that it includes a hard wear-resistant material having a hardness of more than 400 Brinell and being in the form of granules, these granules being cast into a material which serves as a bonding agent, such as e.g. synthetic resin, ceramic materials, rubber or a combination of said materials.” (col. 2, line 29) “The slab . . . is composed from a wear-resistant material, preferably a martensite chromium/nickel alloyed cast iron.” and “ . . . a synthetic resin ceramic material in which the resin component is one of a number of thermosetting resins such as exoxy resin, polyester resin, phenolic plastic, aminoplastic or polyimide resin.” (col. 3, line 46) “As a example may be mentioned that in casting sheet metal having a thickness of 15 millimeter one obtains an HB hardness of between 650 and 700, whereas by quenching martensite cast iron to form granules it is possible to achieve an estimated hardness of up to as much as HB 1000.” The present invention incorporates these and other teachings of Sabel '211.

The following Structural Fiber Present Art background and review focus on:

-   U.S. Pat. No. 214,085, dated Apr. 8, 1879, to Beck (Beck '085) -   U.S. Pat. No. 232,122, dated Sep. 14, 1880, to Hammesfahr     (Hammesfahr '122) -   U.S. Pat. No. 354,788, dated Dec. 21, 1886, to Hickley (Hickley     '788) -   U.S. Pat. No. 2,133,238, dated Oct. 11, 1938, to Slayter et al.     (Slayter et al. '238) -   U.S. Pat. No. 3,255,875, dated Jun. 14, 1966, to Tierney (Tierney     '875) -   U.S. Pat. No. 3,627,466, dated Dec. 14, 1971, to Steingiser,     Phillips & Cass (Steingiser '466) -   U.S. Pat. No. 3,627,571, dated Dec. 14, 1971, to Cass & Steingiser     (Cass '571) -   U.S. Pat. No. 4,842,923, dated Jun. 27, 1989, to Hartman (Hartman     '923) -   U.S. Pat. No. 5,324,563, dated Jun. 28, 1994, to Rogers, Crane & Rai     (Rogers '563)

The present invention utilizes the teachings of Beck '085. Beck '085 teaches of (page 1, paragraph 5) “A flat layer of parallel threads of fine-spun glass of the desired length . . . is placed between some textile fabric . . . and the whole then sewed together by longitudinal stitching . . . at short distances. For sewing I use, by preference, chain-stitch. . . . thus formed . . . a series of channels or tubes, each of them inclosing a number of fine glass threads . . . . ” The present invention incorporates these and other teachings of Beck '085.

The present invention utilizes the teachings of Hammesfahr '122. Hammesfahr '122 teaches of (page 2, line 19) “ . . . making a fabric or cloth, either in whole or in part, of fine-spun glass.” Hammesfahr defines the pre-1880 art with the statement (page 2, line 22) “In the manufacture of so-called glass cloth as heretofore practiced the glass has been introduced only in comparatively small quantities—i.e., in the shape of an ornamental pattern having silk, wool, cotton, or other fibrous material as the basis or ground-work, and in such cases the glass forming such part has of necessity been protected from the action of the reed in weaving by strands of silk or other fibrous material.” Hammesfahr offers (page 2, line 38) “ . . . a fabric made entirely of glass, spun very fine and woven in any suitable manner.” (page 2, line 43) “ . . . and at the same time possess the required degree of toughness . . . and to withstand the beating up . . . without breaking into fine particles.” (page 2, line 49) “The spinning of the glass into threads is accomplished in any well-known manner.” (page 2, line 74) “This fabric is capable of being used for shawls, table-covers . . . and in all articles . . . . ” The present invention incorporates these and other teachings of Hammesfahr '122.

The present invention utilizes the teachings of Hickley '788. Hickley '788 teaches (page 1, line 47) “For example, in manufacturing a carbon . . . I will take, say, two pieces of broom-corn, soak them in a strong alkali until they become soft and gelatinous, and may place them side by side with a certain quantity of spun glass . . . . ” The present invention incorporates these and other teachings of Hickley '788.

The present invention utilizes the teachings of Slayter et al. '238. Slayter et al. '238 teaches of (page 2, col. 1, line 22) “ . . . fabricating . . . yarns composed of a multiplicity of glass fibers, we may use an adhesive . . . which increases the mass integrity of the group of fibers, and inhibits mutual scratching of the fibers . . . ” (page 2, col. 1, line 29) “The . . . coating material may be . . . cellulose products or derivatives, resins, plastics . . . rubber . . . or the like.” (page 4, col. 2, line 30) “Ordinarily the degree of stretch which any individual fiber may possess before breaking, is extremely small, and even for fine fibers, is seldom more than one or two, or at the most about 3 percent . . . the inherent non-stretchability of the fibers . . . ” (page 4, col. 2, line 49) “ . . . we have discovered that by providing yarn having sufficiently fine fibers, which may be intertwisted a sufficiently high degree, the yarns themselves may possess a relatively high degree of elongation, in the order of magnitude of about 10 to 30 percent before breakage.” The present invention incorporates these and other teachings of Slayter et al. '238.

The present invention utilizes the teachings of Tierney '875. Tierney '875 teaches that (col. 1, line 16) “The highest strength reinforced resin structural members are made with sheets of lineally-aligned, contiguous, continuous glass filaments impregnated with thermosetting resin, particularly epoxy resin.” (col. 4, line 66) “Fourteen layers of . . . composite sheet were laid up in . . . crossply fashion, with the direction of filament in each layer offset 90° from those of adjacent layers.” (col. 4, line 72) “The laminated panel had . . . an organic content (resin plus polyester tissue) of 31.2% by weight (about 49% by volume).” (col. 5, line 1) “Test specimens cut from this panel, with their length-wise direction parallel to one set of the filaments, had the following properties: Tensile strength . . . p.s.i. 68,000 Compressive strength . . . psi 80,300 . . .”

(col. 5, line 15) “Another test panel was prepared in the same manner except that the fourteen layers of the composite sheet were laid with all filaments in the same direction. The cured panel . . . had an organic content of 37.4% . . . yielded the following data: Tensile strength . . . p.s.i. 119,000 Compressive strength . . . psi  99,800 . . .” The present invention incorporates these and other teachings of Tierney '875.

The present invention utilizes the teachings of Steingiser '466. Steingiser '466 teaches of (col. 1, line 30) “Graphite fibers having high tensile strength, e.g. over 200,000 p.s.i. . . . have recently become available . . . ” (col. 2, line 6) “Although the term ‘graphite’ is used, the fibers need not be highly crystalline as determined by X-ray diffraction analysis.” The present invention incorporates these and other teachings of Steingiser '466

The present invention utilizes the teachings of Cass '571. Cass '571 teaches (col. 4, line 3) “ . . . of heat-treatment . . . in chlorine at various yarn temperatures as shown by fiber and composite properties are summarized in the table (dwell time about 30 sec.). Fiber Property Temp. ° C. Tensile Strength kp.s.i. 100 260 200 269 300 275 400 282 500 279 600 186 700 131 Control (unheated) 238 . . .” The present invention incorporates these and other teachings of Cass '571.

The present invention utilizes the teachings of Hartman '923. Hartman '923 teaches (col. 3, line 42) “Magnesia aluminosilicate glass fibers used herein are high strength fibers and typically have a tensile strength in excess of about 500,000 psi.” The present invention incorporates these and other teachings of Hartman '923.

The present invention utilizes the teachings of Rogers '563. Rogers '563 teaches that (col. 1, line 51) “The technical basis for this invention is the recognition that the fibers in a cured laminate must be straight or much straighter then they are now in order for the laminate to posses the axial properties predicted by theory.” (col. 2, line 30) “ . . . strenght in excess of 310,000 psi can be demonstrated analytically while current material forms typically yield 250,000 psi. or less.” The present invention incorporates these and other teachings of Rogers '563.

The following Structural Composite Present Art background and review focus on:

-   U.S. Pat. No. 2,035,977, dated Mar. 31, 1936, to Nichols (Nichols     '977) -   U.S. Pat. No. 2,155,121, dated Apr. 18, 1939, to Finsterwalder     (Finsterwalder '121) -   U.S. Pat. No. 2,255,022, dated Sep. 2, 1941, to Emperger (Emperger     '022) -   U.S. Pat. No. 5,613,334, dated Mar. 25, 1997, to Petrina (Petrina     '334)

The present invention utilizes the teachings of Nichols '977. Nichols '977 teaches that (col. 1, line 6) “Reenforced concrete construction is in wide-spread use to-day utilizing two totally different structural materials; namely, concrete and steel. It is a well known fact that the modulus of elasticity of steel is approximately 30,000,000 and that of concrete, while not a constant, may usually be found between 3,000,000 and 4,000,000, so that the modulus ratio, commonly called “n”, varies around 6, 8 or 10 according to the quality of the concrete. Furthermore, steel in tension can support between 30,00 and 60,000 pounds per square inch before reaching its yield point, while the ultimate strength of concrete is usually between 300 pounds and 500 pounds per square inch in tension. In other words, concrete must be expected to stretch but 1/10,000 of its length before cracking, whereas steel will stretch more than 1/1000 of its length and recover without injury or permanent set. The difference between these two deformation characteristics causes much trouble in practice.” (col. 1, line 27) “Especially is this true in the design of a reenforced concrete structural member such as a simple beam in which the theory is that only the concrete above the neutral axis or surface may be depended upon to resist the effects of bending by the compressive stresses found therein and that the steel reenforcement, usually placed near the bottom of the beam, carries all the tensile stresses. Of course, the stress in the matrix below the neutral axis is tensile in character and actually does assist the steel by furnishing a small part of the tensile component in the resisting moment couple. Furthermore, the usual procedure did not stress the reenforcement in any way during the formation of the beam, and because of the shrinkage of the matrix and difference between the steel and concrete tended to form incipient cracks in the bottom of the matrix and put the reenforcement in compression prior to loading.” (col. 1, line 48) “It is also necessary that a good bond be had between the concrete and steel in order that the beam may act as one homogeneous material, and an entire design practice has grown up around the straight line variation between stress and deformation and upon the theory that only a small part of the plane cross-sectional area in a beam takes the compressive stresses. This area is that above the neutral axis, which is relatively high up in the body of the beam. The portion below the neutral axis is not considered to be safely dependable in resisting bending moment. Speaking loosely, the compression stresses forming the compressive component of the resisting moment couple in the present day beam are confined to only a small part of the matrix such as the upper half.” The present invention incorporates these and other teachings of Nichols '977.

The present invention utilizes the teachings of Finsterwalder '121. Finsterwalder '121 teaches that (col. 1, line 1) “The use of ferro-concrete beams for structures of wide-span, especially for bridges, is limited as regards width of span.” (col. 1, line 10) “With increasing width of span of the beam and constant relation of the depth of the structure to the span-width the bending stress increases and thus the quantity of iron necessary with uniform weight per metre of the structure increases linearly. Even with very small span widths of about 13 metres the web-breadth of 25 centimeters no longer suffices for the disposal of the necessary tension irons. Therefore the webs must be broadened, whereby the weight of the structure, calculated on the area of surface, is substantially increased, so that with a freely supported beam the limit is reached with a span width of about 25 metres.” The present invention incorporates these and other teachings of Finsterwalder '121.

The present invention utilizes the teachings of Emperger '022. Emperger '022 teaches of (col. 1, line 1) “ . . . object or structures of reinforced concrete, such as girders, arches, frames, beams and parts thereof.” (col. 1, line 4) “The concrete of structures of such type is subject to cracks in zones where tensile stresses occur under load, and it has been suggested to prevent formation of such cracks and to increase the strength of the structure by preliminary or prestressing all the reinforcements which therefore had to be made of high quality steel.” (col. 1, line 20) “Taking a cylindrical reinforcement embedded in concrete, it has been shown (cf. 0. Graf “Beton und Eisen,” 1910, p. 177 and “Handbuch fur Eisenbetonbau,” 4^(th) ed., first vol., p. 40) that the increase in plasticity of the concrete by reinforcement is very small, and the less the thicker the layer or body of concrete covering the reinforcement is. The maximum plastic or elastic deformation of a layer of 2 mm. thickness around the cylindrical reinforcement has been found to be 0.4% at most before rupture occurs, and if the thickness of the covering cylindrical layer or body amounted to 30 mm., the maximum elongation without rupture has been found to be only 0.2%. Taking a steel the elongation of which amounts to 0.2% at a stress of 400 kg./sq. cm., the covering layer of 30 mm. thickness will yield and form cracks if that stress of 400 kg./sq. cm. is exceeded.” (col. 1, line 39) “Taking however a higher quality steel the elongation of which amounts to 1.4% at a stress of 2800 kg./sq. cm., experiments made by the inventor have shown that a relatively thin cover of concrete will be sufficiently plastic so as to crack only at the yield point of that high quality steel.” (col. 1, line 46) “It has been suggested therefore to use high quality steel for reinforcements of concrete and to arrange them in such numbers and proximity to each other, furthermore to prestress them uniformly to such an extent that due to the bond of the set and shrunk concrete with the individual reinforcements, crack formation was prevented under predetermined maximum load. The compressive stresses exerted by the prestressed reinforcements through the bond upon the concrete were so high that they counter-balanced the tensile stresses exerted upon the concrete by the predetermined maximum load.” (col. 2, line 4) “It has been found however that crack formation is not dangerous as long as cracks, when formed, are prevented from widening in continuous use and under recurrent load, and substantially close when the load is moved.” (col. 5, line 41) “Corners of reinforced concrete structures are particularly subject to hair line cracking and should be reinforced in the way to be derived from FIG. 3 without further comment.” (col. 5, line 53) “Most surprisingly, the tensile strength of the concrete, as small as it may be, can also be taken into consideration in calculating the structure according to the invention.” (col. 5, line 68) “Now, in calculating the structure, its cross section has to be taken into consideration in which the largest tensile stress occurs under predetermined maximum load. It is common to consider in such case only the total tensile strength of the reinforcements positioned in the stressed area of that cross section. If however the tensile stress . . . in that area does not exceed . . . ” the tensile unit strength of the concrete “ . . . the tensile strength of the concrete in that area can be taken into consideration in addition to that of the total tensile strength of the reinforcements, main and additional, arranged in that area.” The present invention incorporates these and other teachings of Emperger '022.

The present invention utilizes the teachings of Petrina '334. Petrina '334 teaches (col. 1, line 24) “Concrete is strong under compression, but relatively low in strength under tension. When a structural member such as a beam is made of concrete, it is under both compressive stress at the top of the beam and tension at the bottom of the beam. Thus a concrete beam would tend to fail by being cracking and pulling apart at the bottom, where the stress is tensile. The same is true of concrete roads, or any other application where tensile forces will be applied to concrete.” (col. 1, line 32) “This can be overcome by placing reinforcement where it is necessary for structural members to resist tensile forces. The result is called ‘reinforced concrete.’ The reinforcement is typically in the form of steel bars (usually called ‘reinforcing bars’ or simply ‘rebars’) or welded wire fabric (in the case of flat areas such as roads, floors, or other concrete slabs).” (col. 1, line 39) “In a concrete beam, the steel rebar is placed in the lower part of the beam, so that the tensile forces are countered by the reinforcement. The steel reinforcement is bonded to the surrounding concrete so that stress is transferred between the two materials.” (col. 1, line 44) “In a further development the steel is stretched before the development of bond between it and the surrounding concrete. When the force that produces the stretch is released, the concrete becomes precompressed in the part of the structural member that is normally the tensile zone under load. The application of loads when the structure is in service reduces the precompression, but generally tensile cracking is avoided. Such concrete is known as ‘prestressed concrete’.” The present invention incorporates these and other teachings of Petrina '334.

The following Prestressed Structural Composite Present Art background and review focus on:

-   U.S. Pat. No. 851,118 dated Apr. 23, 1907, to Chadwick (Chadwick     '118) -   U.S. Pat. No. 903,909 dated Nov. 17, 1908, to Steiner (Steiner '909) -   U.S. Pat. No. 1,684,663 dated Feb. 7, 1925, to Dill (Dill '663) -   U.S. Pat. No. 1,781,699 dated Nov. 18, 1930, to Parmley (Parmley     '699) -   U.S. Pat. No. 2,303,394, dated Dec. 1, 1942, to Schorer (Schorer     '394) -   U.S. Pat. No. 2,319,105 dated May 11, 1943, to Billner (Billner     '105) -   U.S. Pat. No. 2,435,998, dated Feb. 17, 1948, to Cueni (Cueni '998) -   U.S. Pat. No. 2,453,079 dated Nov. 2, 1948, to Rossmann (Rossmann     '079) -   U.S. Pat. No. 2,660,049, dated Nov. 24, 1953, to Maney (Maney '049) -   U.S. Pat. No. 2,781,658 dated Feb. 19, 1957, to Dobell (Dobell '658) -   U.S. Pat. No. 2,857,755 dated Oct. 28, 1958, to Werth (Werth '755) -   U.S. Pat. No. 2,869,214 dated Jan. 20, 1959, to Van Buren (Van Buren     '214) -   U.S. Pat. No. 3,950,905 dated Apr. 20, 1976, to Jeter (Jeter '905) -   U.S. Pat. No. 6,170,209 dated Jan. 9, 2001, to Dagher, et al.     (Dagher, et al. '209)

The present invention utilizes the teachings of Chadwick '118. Chadwick '118 teaches of (page 2, col. 1, line 12) “ . . . a flexible cable on which a series of sleeves are strung which, when jammed tightly together, form a rod of sufficient stiffness so as not to buckle or bend when in use. Upon loosening the sleeves, the cable and sleeves can be wound on a drum . . . ” (page 2, col. 1, line 40) “The rod is made ready for use by jamming the sleeves 11 tightly together. This is done by screwing down the nut 15 . . . . ” The present invention incorporates these and other teachings of Chadwick '118.

The present invention utilizes the teachings of Steiner '909. Steiner '909 teaches that (page 3, col. 1, line 16) “ . . . a very high initial strain is imparted to the most important tension-rods, while the concrete is gaining in coherence and hardness within the next few hours, after being placed.” (page 3, col. 1, line 29) “The adjustment of the length of the tension-rods must begin shortly after placing a suitable block or portion of the structure and must be repeated while the concrete is shrinking and tightened up gradually to a higher strain as the concrete gains in hardness. Since there is no appreciable bond between the concrete and the rods at the start of this operation, while at the outside of the concrete resistance against pressure soon increases, there is provided an anchorage at the ends . . . ” The present invention incorporates these and other teachings of Steiner '909.

The present invention utilizes the teachings of Dill '663. Dill '663 teaches of limitations on elasticity of tensile members of prestressed structural composites (page 4, col. 2, line 1) “It is the present practice to use mild steel because since the modulus of elasticity of mild, semi-hard, and hard steel is practically the same there is no advantage within limits in the use of hard steel. The distortion of a reinforced concrete structure sufficient to develop the full strength of mild steel, is sufficient to completely ruin the concrete.” Dill points out the general engineering properties of concrete and steel and some of the composite-structural consequences of such. (page 2, col. 2, line 93) “It is a scientific fact well known to all concrete engineers, that the modulus of elasticity of steel is approximately 30,000,000 while that of concrete is about 3,000,000, or approximately one-tenth that of steel. The strength of steel in tension is approximately 30,000 pounds per square inch, while that of concrete is only about 300 pounds. In other words, concrete will stretch about 1/10,000 of its length before cracking, and steel will stretch about 1/1,000 of its length before reaching its yield point. So that if a concrete post, or beam, or pile, or floor, or any structure of concrete and steel that is called upon to resist a tensile strain, is stretched 1/10,000 of its length the concrete will crack. If it is stretched 1/1,000 of its length the concrete will crack in ten different places, or if in a lesser number of places the cracks will be relatively wider. The cracks will form in advance of the full loading of the steel.”

Dill '663 expanses on engineering issues of concrete-steel composite design. (page 3, col. 1, line 33) “(1) Concrete, during the setting process, shrinks. The degree of shrinkage is variable. In general the richer the concrete in cement the greater the shrinkage.

(2) Concrete, after the set is apparently completed, will shrink with loss of moisture.

(3) Concrete will shrink under compression at the same rate that it will expand under tension.

Therefore, when the steel is held under tension and the plastic concrete is poured about it, what happens is this: As the concrete is initially setting it shrinks or attempts to shrink, or in other words, it is in tension. If later it dries out it will shrink some more and increase its tension, so that the product of concrete and steel will lose part or all of the tension placed in the steel and may, in addition, develop such tensional strains on the concrete as to cause the concrete to crack. In the very exceptional case where the mixture is very thin and the concrete is left moist so that it does not shrink, the tension of the steel allowed to come on the concrete will compress it so that part of its tension is lost and the product is not perfect even in that case. In reinforced concrete, as ordinarily manufactured, no tension is placed in the steel during the manufacture, and the tension developed by the concrete almost always results in compression of the steel, relieved in part by numerous cracks in the concrete. It is to be remembered that this relief is in part only. The sections of concrete between the cracks is not at rest but is in tension and being in tension holds the steel in compression. Each section is in a state of unstable equilibrium.” The present invention incorporates these and other teachings of Dill '663

The present invention utilizes the teachings of Parmley '699. Parmley '699 teaches the limitations of a homogeneous material which has asymmetric engineering properties whereby its compressive strength is significantly greater than its tensile strength, i.e. concrete or cast iron. (page 2, col. 2, line 89) “With homogeneous concrete, contraction can take place with practically no internal stress being set up within the mass of the concrete. The resulting . . . will therefore, when subjected to bending stresses of loading, be able to withstand these stresses up to the normal limit of the tensile strength of the concrete. The modulus of the concrete in tension therefore, usually runs two or three hundred pounds per sq. in. and it is this transverse strength which makes the . . . use . . . possible.” The present invention incorporates these and other teachings of Parmley '699.

The present invention utilizes the teachings of Schorer '394. Schorer '394 teaches that (col. 1, line 8) “Various methods and means have been devised for subjecting concrete to initial compression for the purpose of reducing or eliminating tensile stresses in the concrete. The prior art methods and means include deformation of the moulds and thereby compressing the concrete in the mould while the concrete hardens and/or applying initial tension forces to the reinforcing steel and maintaining such forces until the concrete has hardened and then releasing said forces and thereby transmitting them to the adjacent concrete and setting up compression therein. With some of the prior art methods the bond between the reinforcements and the concrete is destroyed and monolithic action is not possible. Due to the fact that the reactions of the tensioning forces are generally transmitted to the moulds the methods and devices proposed so far are expensive and their application is limited . . . . ” (col. 5, line 7) “After releasing the compression member the initial tension . . . is somewhat reduced due to the elastic and plastic deformation and skrinkage of the concrete, the proportion depending on the amount of prestress. The balance is available for the initial compression of the concrete. The design and proper arrangement of the prestressed reinforcing units permits the complete elimination of all tensile stresses in the concrete also under extreme load conditions.” The present invention incorporates these and other teachings of Schorer '394.

The present invention utilizes the teachings of Billner '105. Billner '105 teaches of (page 2, col. 1, line 1) “ . . . reinforced plastic bodies and methods of producing them . . . . By its very nature, concrete is intended to assume compressive stresses only, while its reinforcing elements are relied upon to receive the tensile stresses.” Billner teaches that prestressing such composite structures can be (page 2, col. 2, line 8) “ . . . obtained by thermally expanding the reinforcing elements after the plastic body has hardened. This is accomplished by forming the plastic body about the reinforcing element and releasing any bond between the body and the element so that the element may be expanded with respect to the body, whereupon the element is permitted to partially contract so as to bear upon the body and produce compressive stresses therein . . . . The reinforcing element is expanded preferably by the application of heat . . . ” (page 2, col. 2, line 41) “When the reinforcing element has expanded an amount sufficient to impose the desired stresses upon subsequent contraction, it is suitably secured against excessive contraction so that the desired amount of its contracting force will be applied to produce compressive stresses within the body.” The present invention incorporates these and other teachings of Billner '105.

The present invention utilizes the teachings of Cueni '998. Cueni '998 teaches that (col. 1, line 10) “Prestressed reinforced concrete had previously been proposed and some use thereof has been made in structures. However, it has been subject to numerous disadvantages. For instance, it has been customary to apply such prestressing in the field, but the prestressing of the reinforcing bars has required such a large force that it was difficult to provide the necessary machinery and the auxiliary equipment together with the skilled labor, to allow it to be economically applied. It has also been practically impossible to obtain uniform results in the field because of the practical impossibility of obtaining uniform and reproducible conditions of operation.” (col. 1, line 34) “Another construction which had previously been used embodied a steel beam which was connected to a concrete slab by suitable shear reinforcements so that the parts did act as a single unit, the steel sustaining the tensile stresses and the concrete sustaining the compressive stresses.” (col. 2, line 10) “By prestressing the high tensile steel reinforcement up to 70% of its strength before the concrete is poured, and releasing the prestressing force after the concrete has set, such compressive stresses will be introduced into the concrete, that it can be stressed in tension as well as in compression without developing cracks, and the full strength of the reinforcement is developed.” (col. 4, line 37) “If more than the design load is applied, the compressive stresses in the bottom of the concrete will gradually change to tensile stresses and finally, when the tensile strength of the concrete is reached, the concrete will crack. From then on the section will act like a reinforced concrete . . . beam and has to be designed as such.” (col. 4, line 48) “ . . . three steps are required in computing the stresses of such a beam. a. For the computation of the stresses in the prestressed beam due to the dead load: It is assumed that the precast beam is acting like any prestressed reinforced concrete beam. b. For the computation of the stresses in the composite section due to the live load: It is assumed that the composite section acts in a similar way as a steel beam composite section, the poured-in-place concrete slab sustaining the compressive stresses, and the prestressed concrete of the precast beam sustaining the tensile stresses. c. For the computation of the ultimate load: It is assumed that the composite section acts like a reinforced concrete . . . beam section, the poured-in-the-field concrete slab sustaining the compressive stresses and the bottom steel of the precast beam, the tensile stresses.” (col. 4, line 67) “All prestressed beam composite sections have to be checked for ultimate load, for the assumption of a certain working stress for the steel does not always mean a corresponding factor of safety as it does in other types of construction.” (col. 4, line 72) “Such a design is very unusual and together with the different stress diagram proves the novelty of the construction that is the object of the present invention.” The present invention incorporates these and other teachings of Cueni '998.

The present invention utilizes the teachings of Rossmann '079. Rossmann '079 teaches of (page 2, col. 1, line 9) “ . . . a metallic load receiving and transmitting rod or bar which will tend to decrease its elongation from zero to maximum load in use, and which will at the same time tend by reason of deformation imposed thereon to increase its tensile strength and also to extend fatigue life.” Rossmann '079 is not a structural composite. Rossmann '079 identifies the structural concern regarding metallic structural fatigue. The present invention incorporates these and other teachings of Rossmann '079

The present invention utilizes the teachings of Maney '049. Maney '049 teaches that (col. 1, line 4) “Structural compression members have heretofore been provided which include a core of concrete or the like bound with a helical wire or band of steel or the like, but such members have been unsatisfactory for the reason that under load the core would fail before the lateral deformation thereof produced sufficient tension in the helical band to permit the band to perform its function of strengthening the core against failure, or the helix would fail as a column before it would act to restrain deformation of the core. In accordance with the present invention, the shell for the core is provided by a helical wire or band of steel or the like having a high elastic limit which is tensioned about the core in manufacture. Since the shell is always under tension, a compressive load on the core cannot cause failure of the core or of the shell as a column before the shell becomes effective to restrain the lateral deformations of the core resulting from the compressive force.” The present invention incorporates these and other teachings of Maney '049.

The present invention utilizes the teachings of Dobell '658. Dobell '658 teaches that (page 4, col. 1, line 30) “(f)or many years, mild, low strength steel reinforcing was simply embedded in ordinary concrete and the result was an improvement in the strength of the concrete and some resistance to cracking and other failures. Later there was an attempt to place this reinforcement under tension so that it would have a compressive effect upon the concrete. This slightly improved the construction although the success of this effort was not great because those who did it did not appreciate the fact that concrete would flow slightly under pressure and thus that the tension on the reinforcement would be reduced practically back to zero. Also, under tension the reinforcement itself would suffer some permanent elongation that would add to this reduction of tension. (page 4, col. 1, line 44) “Accordingly, the tensioning of the reinforcement was generally considered to be of great importance until recently, when some of the factors influencing the effectiveness of reinforcement became better known and it was found that if steel wire having very high tensile strength was used and was placed under a very high tensile strength was used and was placed under a very high tension, then, although a part of this tension was lost by plastic flow and shrinkage in the concrete and permanent elongation or “creep” in the wire, nevertheless, sufficient tension would remain in the wire and sufficient compression would remain on the concrete to cause a major increase in the load carrying capacity of the concrete and a major increase in the resistance of the concrete to cracking and the like. This represented such a complete departure from previously known facts as to present a completely new concept of reinforced concrete and hence, this high tensioned wire reinforcing of concrete was properly considered to furnish a completely new and different approach to reinforced concrete construction.” The present invention incorporates these and other teachings of Dobell '658.

The present invention utilizes the teachings of Werth '755. Werth '755 teaches the present art method and means of prestressing lexicon (page 4, col. 1, line 24) “ . . . the following terms shall have the indicated meanings . . . (italics in original) . . .

Prestressing.—denotes the action upon a structure of applied forces calculated to impart stresses of sufficient magnitude to permanently neutralize undesirable stresses of opposite sign due to load.

Anchor.—denotes the means by which the prestressing force is transferred from the tensile unit to the structure.

Structure.—defines structures and structural members, units, elements or portions thereof.

Concrete structure.—defines a structure made of concrete or any other material capable of withstanding compressive forces.

Grout.—defines any hydraulically compressible material used for the filling of cavities in structures.

(page 4, col. 1, line 41) “In order to illustrate the shortcomings of the prior art prestressing methods . . . a resume of the principal features of prior art prestressing methods is given as follows: (italics in original)

Type 1. Pre-tensioning.—The prestressing force is applied externally to the prestressing units, positioned inside of the forms prior to the pouring or casting of the concrete.

Type 2. Post-tensioning at anchor terminals.—The structure is poured monolithically, i.e., in one continuous operation, or is formed by assembling prefabricated members and wherein cavities, if used, are left for the prestressing units only. The prestressing force is then applied externally to the prestressing unit at terminals only or at terminals and intermediate anchors, by means of removable mechanical tools or devices, such as jacks and wrenches. In order to apply prestressing force at the intermediate anchors, the latter have to be made accessible by means of temporary openings in the structure. Such openings subsequently have to be filled.

Type 3. Post-tensioning at joints.—The structure is divided by joints into two or more portions and is held together by prestressing units only, which units are placed in cavities and anchored in the concrete. The prestressing force is applied externally at the joints by means of jacks, pressure pillows, cells, etc., or by gravity action. The joints have to be filled in after the structure is prestressed. In some systems the prestressing devices remain in the structe permanently. This circumstance does not alter the fact that the structure is prestressed externally.” The present invention incorporates these and other teachings of Werth '755.

The present invention utilizes the teachings of Van Buren '214. Van Buren '214 teaches of (page 3, col. 1, line 21) “ . . . methods for making so-called prestressed concrete bodies or members is to cast the concrete in a suitable mold provided with removable mandrels or other core means which, when removed after the concrete has set, will leave holes therethrough, through which wires or cables are threaded. Such wires or cables are then heavily tensioned by the use of jacks which apply tensioning forces to the wire ends, which forces react against the body of concrete causing the latter to be subjected to heavy compression . . . such wired are then permanently anchored at their ends to maintain the tension therein by the use of suitable end anchorage means which, after same is applied, permits the jacks to be removed while the concrete remains under permanent compression. It has been proposed to then introduce cement mortar or the like in fluid condition along the tensioned wires in the holes in the concrete for the purpose principally of protecting the wires against corrosion. Other experts have advocated the injection of cement grout under pressure into the holes along the wires in such a manner as to securely bond the wires in place under tension so that the end anchorage means may thereafter be removed for reuse elsewhere . . . ” The present invention incorporates these and other teachings of Van Buren '214.

The present invention utilizes the teachings of Jeter '905. Jeter '905 teaches of a “(m)ethod for prestressing a structural member.” “The apparatus disclosed includes an elongated reinforcing member with stress anchors attached to each end for embedding in a body of hardenable material, such as concrete, when the material is cast into the desired shape for the structural member. The apparatus includes a member containing potential energy. After the material has hardened, the potential energy is released to place the material between the stress anchors in compression to prestress the structural member before it is placed in service.” The present invention incorporates these and other teachings of Jeter '905.

The present invention utilizes the teachings of Dagher, et al. '209. Dagher, et al. '209 teaches of “ . . . a prestressing system for wood elements and structures and a method from prestressing wood beams. In its most basic form, the system for prestressing structures comprises a plurality of members arranged in a predetermined configuration, at least one non-metallic prestressing tendon, having a material stiffness less than that of steel, disposed in such a manner as to fasten together the members, and stressing means attached to at least one end of the prestressing tendon to exert a tensile force on the tendon and an equal and opposite compressive force drawing the members together. In the preferred embodiment, the tendons are manufactured from fiber reinforced plastic and the members are arranged in side by side relation to form a deck. The deck includes a series of aligned holes through the members, through which the prestressing tendons pass and are secured and prestressed. In alternate embodiment of the invention, prestressing tendons are used to secure and prestress stress laminated T sections and box sections and to secure timber trusses. The present invention is also directed to a system and method for prestressing beams. In its most basic form, the system comprises at least one nonmetallic tendon, at least one opening disposed longitudinally through a lower portion of the element, a pair of anchors disposed at the ends of each prestressing tendons, and a pair of bearing plates disposed between the anchors and the bearing surface of the beam. In operation, the tendons are disposed within the opening, the bearing plates are disposed against the bearing surfaces and the anchors are tightened such that a tensile force is exterted on the tendons and such that said bearing plates exert a substantially equal an opposite compressive force on the element beam. In an alternate embodiment, the opening is filled along the tendon with a resin and the anchors are removed after the resin has cured.” The present invention incorporates these and other teachings of Dagher, et al. '209.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a fatigue and metal embrittlement resistant structure for civil and structural applications which may be assembled in a variety of configurations and sizes.

It is another object of the present invention to provide a structural means for assembly of a number of structural elements and thereby permit erection of multiple element structures in a wide range of configurations.

It is still another object of the present invention to provide a structural assembly that obviates the fatigue and/or metal embrittlement problems associated with welded metallic structures.

It is a further object of the present invention of applying a prestressing force during assembly and/or to the assembled structural composites when such structural composites consist of one or more elements having asymmetric engineering materials properties, thereby structurally allowing use of the more desired of the asymmetric engineering properties.

It is yet another object of the present invention of applying a prestressing force during assembly and/or to the assembled structural composite(s) when such structural composite(s) consist of one or more elements having fatigue susceptible metallic properties.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is graph showing relationship between ductile iron “Hardness, Brinell” (X-axis) and ductile iron compressive yield strength (Y-axis).

FIG. 2 is a isometric-view photo of sample ferrous member 1 showing open channels 2 (with edge-distance 4 providing overall rigidity to completed structural composite and protection of tensile fibers from side-impact) for non-metallic tensile member fibers and passageway 3 for said fiber placement thru said ferrous member to intended compressive region. Intended compression region 6 is at bottom; intended tensile region 7 at top; intended neutral-axis 5 near region of bottom of open channels.

FIG. 3 is a side-view of an assembled structural composite subjected to three-point-bend test, after structural failure, failure mode being tensile failure of non-metallic fiber. Compression region 6 is at top of composite structure, tensile region 7 is at bottom of composite structure. Hot-dip galvanized ferrous material 8 was bonded to fiberglass/resin 9 (fiberglass is transparent). Tensile tear 10 failure mode identifies structural composite unbalanced in design in favor of ferrous member element over non-metallic fiber member element. No apparent delaminating between structural elements.

FIG. 4 is a side-view of another assembled structural composite about to be three-point-bend tested. Compression region 6 is at top of composite structure, tensile region 7 is at bottom of composite structure. Hot-dip galvanized ferrous material 8 was bonded to fiberglass/resin 9.

FIG. 5 is close-up of assembled structural composite, shown in FIG. 4, after subjected to three-point-bend test, location of applied load is 11, failure mode being tensile failure of ferrous material. Compression region 6 is at top of composite structure, tensile region 7 is at bottom of composite structure. Hot-dip galvanized ferrous material 8 was bonded to fiberglass/resin 9 (fiberglass is transparent). Tensile tear 10 failure mode identifies structural composite unbalanced in design in favor of non-metallic fiber member element over ferrous member element. No apparent delaminating between structural elements.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention is a structural-composite composed of a ferrous member (see FIG. 2) 1 such as cast-iron, a non-metallic fiber member such as fiberglass and a resin. The cast-iron member is portioned so as to completely occupy the compressive region of the structural-composite when said structural-composite is subjected to design bending moment loads. Said cast-iron member extends beyond the intended neutral-axis of the structural-composite into the intended tensile region of said structural-composite when said structural-composite is subjected to design bending moment loads. Said cast-iron member's surfaces exposed to tensile stresses when said structural-composite is subjected to design bending moment loads are prepared to effect shear-transfer to resin(s) applied to said surfaces. Such surface preparation(s) may include projections and/or voids formed when the member was cast and/or post-cast abrasion, pitting, grinding or cutting. Such surface preparation(s) may include metallurgical processes such as hot-dip zinc and/or aluminum and/or nickel. Such metallurgical processes are intended to form alloy layer(s) providing shear-transfer to the chosen resin(s) and said chosen resin(s) providing shear-transfer to said fiberglass member. The fiberglass member is portioned so as reside completely within the tensile region of the structural-composite when said structural-composite is subjected to design bending moment loads.

An embodiment of the present invention is a structural-composite composed of a ferrous member such as cast-iron and a non-metallic fiber member such as fiberglass and a resin. The cast-iron member is portioned so as to completely occupy the compressive region of the structural-composite when said structural-composite is subjected to design bending moment loads. Said cast-iron member extends beyond the intended neutral-axis of the structural-composite into the intended tensile region of said structural-composite when said structural-composite is subjected to design bending moment loads. Said cast-iron member's surfaces exposed to tensile stresses when said structural-composite is subjected to design bending moment loads are prepared to effect shear-transfer to resin(s) applied to said surfaces. Such surface preparation(s) may include projections and/or voids formed when the member was cast and/or post-cast abrasion, pitting, grinding or cutting. Beginning in the intended tensile region of the ferrous member, open channels or open voids may be formed, either at time of casting or post-casting, extending toward or beyond the structural-composite's intended neutral-axis, such channels or voids providing both additional surface-area for bonding the non-metallic fiber thereby providing more shear-transfer and providing additional tensile strength throughout the structural-composite's tensile region. Surface preparation(s) may include metallurgical processes such as hot-dip zinc and/or aluminum and/or nickel. Such metallurgical processes are intended to form alloy layer(s) providing shear-transfer to the chosen resin(s) and said chosen resin(s) providing shear-transfer to said fiberglass member. The fiberglass member is portioned so as reside completely within the tensile region of the structural-composite when said structural-composite is subjected to design bending moment loads.

Preffered Embodiment

The preferred embodiment of the present invention is a structural-composite composed of cast-iron members, fiberglass members and resins. The cast-iron members are portioned so as to completely occupy the compressive region of the structural-composite when said structural-composite is subjected to design bending moment loads. Said cast-iron members extend beyond the intended neutral-axis of the structural-composite into the intended tensile region of said structural-composite when said structural-composite is subjected to design bending moment loads. Some said cast-iron member's surfaces exposed to tensile stresses when said structural-composite is subjected to design bending moment loads are prepared to effect shear-transfer to resin(s) applied to said surfaces. Such surface preparation(s) may include projections and/or voids formed when the member in question was cast and/or post-cast abrasion, pitting, grinding or cutting. Beginning in the intended tensile region of the ferrous member, open channels or open voids may be formed, either at time of casting or post-casting, extending toward or beyond the structural-composite's intended neutral-axis, such channels or voids providing both additional surface-area for bonding the non-metallic fiber thereby providing more shear-transfer and providing additional tensile strength throughout the structural-composite's tensile region. Surface preparation(s) may include metallurgical processes such as hot-dip zinc and/or aluminum and/or nickel. Such metallurgical processes are intended to form alloy layer(s) providing shear-transfer to the chosen resin(s) and said chosen resin(s) providing shear-transfer to said fiberglass member. Said chosen resin(s) should be catalyst-sensitive to the metal forming the ferrous alloy. The fiberglass member is portioned so as reside completely within the tensile region of the structural-composite when said structural-composite is subjected to design bending moment loads. The fiberglass strand should be of a continuous loop recessed into said open channels or the like in the ferrous material. Where the design use may cause the fiberglass to receive direct physical shock or impact a cover of protective material may be added. 

1. The means and methods of making a structural member of reinforced ferrous material comprising using an amount of non-metallic fiber reinforcement structurally attached to said ferrous material.
 2. An assembly as in claim 1, wherein the said ferrous material surface and near-surface is metallurgically alloyed with another metal before attachment of said non-metallic fiber reinforcement.
 3. An assembly as in claim 2, wherein said ferrous-alloy surface is partly removed before attachment of said non-metallic fiber reinforcement.
 4. An assembly as in claim 3, wherein attachment of non-metallic fiber reinforcement is with a resin.
 5. An assembly as in claim 4, wherein said resin is catalyst-sensitive to the alloying metal.
 6. An assembly as in claim 2, wherein the said ferrous material surface and near-surface is metallurgically alloyed via the hot-dip galvanizing process before attachment of said non-metallic fiber reinforcement.
 7. An assembly as in claim 6, where in said ferrous-zinc alloy surfaces are partly exposed by removal of some of the galvanized ferrous material's external zinc surface before attachment of said non-metallic fiber reinforcement.
 8. An assembly as in claim 1, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 9. An assembly as in claim 2, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 10. An assembly as in claim 3, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 11. An assembly as in claim 4, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 12. An assembly as in claim 5, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 13. An assembly as in claim 6, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 14. An assembly as in claim 7, wherein said non-metallic fiber reinforcement is substantially in excess of that warranted, said ferrous material is compressed before being structurally attached to said non-metallic fiber reinforcement and after affecting said structural attachment, releasing said ferrous material to tension the said non-metallic fiber reinforcement throughout its structural attachment with said ferrous material.
 15. An assembly as in claim 4, wherein said compression of said ferrous material is achieved by reducing its temperature below its intended ambient temperature range use.
 16. An assembly as in claim 15, wherein temperature reduction of ferrous material is achieved with the aid of thermoacoustical means and methods.
 17. An assembly as in claim 14, wherein voids are present within the ferrous material for the purpose of using cabling to apply a compressive force on said ferrous material.
 18. An assembly as in claim 1, wherein said non-metallic fiber reinforcement element is structurally attached to more than one ferrous material element.
 19. An assembly as in claim 1, wherein said ferrous material element is structurally attached to more than one non-metallic fiber reinforcement element.
 20. An assembly as in claim 1, wherein said non-metallic fiber reinforcement electrically insulates said ferrous material. 